IOSYS
IOSYS (イオシス) is a Japanese doujin music circle and production team founded on October 10, 1998, in Sapporo, Hokkaido.[1] The group specializes in vocal and instrumental arrangements of music from the Touhou Project series, alongside original compositions for anime, rhythm games, virtual live streamers, and DJ performances.[2] Renowned for its humorous, high-energy "denpa" style tracks that blend pop, rock, and electronic elements, IOSYS has produced viral internet sensations such as Cirno's Perfect Math Class (from the 2008 album Touhou Hyosetsu Kashu) and Marisa Stole the Precious Thing (from the 2006 album Touhou Otome Bayashi), which have amassed millions of views on platforms like YouTube and Nico Nico Douga.[2][3] These songs exemplify the circle's focus on meme-inspired lyrics and catchy melodies, often featuring vocalists and collaborators who bring playful narratives to life.[4] Comprising a core team of creators—including composers like ARM, uno (RoughSketch), and D.watt—and supporting members such as vocalists like Ayu, IOSYS operates independently without a major label, releasing albums primarily at events like Comiket, Reitaisai, and M3.[4] Beyond doujin activities, the team has contributed to commercial works, including the opening theme for the anime Robot Girls Z and tracks for games like Blue Archive and Dance Dance Revolution.[2] With over 25 years of activity, IOSYS continues to innovate through digital releases, merchandise, and online content via its official YouTube channel and Booth store.[1]History
Founding and early years (1998–2005)
IOSYS was founded on October 10, 1998, by Youhei Kimura, known professionally as ARM, as a one-person doujin circle based in Sapporo, Hokkaido, Japan.[5] Initially focused on creating original music, ARM handled composition and production single-handedly, sharing early works through internet forums popular among doujin enthusiasts.[6] This grassroots approach allowed the circle to build a small but dedicated local following without immediate commercial ambitions. In its formative years, IOSYS began self-producing and distributing physical CDs of original tracks starting in 1999, marking the circle's entry into tangible music releases. Notable early albums included 20kHz, an instrumental collection composed entirely by ARM, and contributions to game soundtracks like End of Holiday Original Sound Trax.[7] The group participated in local doujin events in the Sapporo area, such as smaller conventions and markets, which provided opportunities for direct fan interaction and sales before gaining broader attention. These activities remained regionally confined, emphasizing community-driven distribution over national exposure. ARM remained the primary composer during this period, while Yoshimi Youno (夕野ヨシミ) contributed as an early lyricist, adding vocal elements to select original pieces and helping shape the circle's creative direction.[8] Operating from Sapporo, IOSYS maintained a modest structure as a doujin collective, with operations centered on collaborative yet informal contributions from local talents. By 2005, these foundations had positioned the group for expansion, including a formal transition to a yūgen gaisha limited company structure in 2006.[6]Rise to fame and expansion (2006–present)
IOSYS's breakthrough came in 2006 with the release of their first major Touhou Project arrangement album, Tōhō Kazakuraen (Phantasmagoria Mystical Expectation), on May 21 at Reitaisai 3. This instrumental-focused collection, featuring rearrangements of themes from games like Embodiment of Scarlet Devil and Perfect Cherry Blossom, marked the group's entry into the popular doujin genre and quickly gained traction among fans for its innovative electronic and rock styles. Shortly before, in April 2006, IOSYS incorporated as Yūgen Gaisha (limited company) to formalize operations amid growing demand.[9] The group expanded rapidly through doujin events like Comiket and online sales via their dedicated shop, amassing over 270 album releases by 2025, including vocal arrangements, club mixes, and best-of compilations. Their official website, iosysos.com, served as a central hub for promotions and digital distribution, while the web radio program Nurupo Housoukyoku (launched in 2004) provided ongoing engagement through broadcasts, artist talks, and previews, boosting visibility in the doujin community. These efforts solidified IOSYS's position as a prolific contributor to Touhou music, with consistent output at major events like Reitaisai and Comiket.[10][11][12] In recent years, IOSYS continued innovating with high-profile collaborations and releases. In August 2024, they partnered with McDonald's Japan and Team Shanghai Alice for a parody advertisement of their hit "Marisa Stole the Precious Thing," adapting the track to promote the Samurai Mac burger in an animated spot that echoed Touhou's whimsical style. This marked a rare mainstream crossover for the group. On May 5, 2025, at Reitaisai 22, they debuted TOHO BOOTLEGS 9, the latest in their club arrangement series, featuring seven tracks blending Touhou themes with modern electronic beats, available initially at the event before wider digital release.[13][14]Musical style
Arrangement techniques
IOSYS's arrangements of Touhou Project background music (BGM) prominently feature a fusion of electronic, rock, and denpa genres, transforming the original instrumental tracks into dynamic vocal-inclusive pieces suitable for doujin events.[15][16] These rearrangements often accelerate the original tempos to create high-energy rhythms, as seen in their hardcore techno-infused remixes that emphasize fast-paced beats and driving basslines.[17] Synthesizers play a central role, layering synthetic sounds over the core melodies to add texture and modern club-like appeal, while occasional incorporation of quirky, meme-inspired audio samples enhances the playful, humorous tone without altering the foundational structure.[18] The production process relies on collaborative composition among circle members, where initial melodies—often crafted by key arrangers like ARM—serve as foundations that are subsequently refined and expanded by others, such as D.watt, through iterative adaptations in arrangement and instrumentation. This team-based approach allows for diverse stylistic integrations, ensuring tracks blend Touhou's melodic essence with contemporary electronic elements while maintaining coherence across multi-track albums.[19] Over time, IOSYS's techniques have evolved from rudimentary doujin-style mixes in their early years to more sophisticated productions optimized for major events like the Hakurei Shrine Reitaisai, incorporating professional-grade mixing and event-specific rhythmic enhancements for live performance compatibility.[20] This progression reflects a shift toward polished, release-ready tracks distributed via digital platforms and event CDs, prioritizing broad accessibility and fan engagement.[21]Lyrics and themes
IOSYS's lyrics prominently feature parody and satire, frequently incorporating references to internet memes, pop culture, and the distinctive quirks of Touhou Project characters to create humorous reinterpretations of the source material.[15] For example, the song "Marisa Stole the Precious Thing" satirizes Marisa Kirisame's kleptomaniac tendencies through exaggerated, playful verses that highlight her mischievous personality, turning a simple character trait into a viral comedic motif within the fandom.[15] Similarly, "ケロ⑨destiny" (Cirno's Perfect Math Class) parodies popular Nico Nico Douga videos with rapid-fire puns and absurd scenarios, such as Cirno's bungled arithmetic lessons, blending Touhou lore with online humor to emphasize the fairy's dim-witted charm. Recurring themes revolve around absurdity, often juxtaposing fantastical Gensokyo elements with mundane frustrations or pop culture tropes.[15] This witty, satirical approach is a signature of lyricists such as Yoshimi Youno, whose contributions infuse the texts with clever wordplay and ironic commentary on character dynamics.[22] Album extras further amplify this by parodying anime themes, such as the Haruhi Suzumiya ending in Tōhō Tsukitōrō, merging Touhou motifs with broader cultural satire. The lyrical structure typically employs short, catchy verses optimized for synchronization with fast-paced flash animations, relying on dense puns and rhythmic delivery to maintain energy and humor.[15] Over time, IOSYS has evolved to include more collaborative elements, as seen in compilations like Miko BEST Toho of IOSYS, which feature vocalist miko and celebrate recurring motifs while appealing directly to dedicated listeners.[15]Flash videos
Key productions
IOSYS's debut flash video, "Marisa Stole the Precious Thing" (魔理沙は大変なものを盗んでいきました), released on August 13, 2006, parodied the Touhou Project character Marisa Kirisame's thieving antics through humorous lyrics set to an arrangement of the track "Doll Judgment ~ The Girl Who Plays with People's Shapes."[23] Created in collaboration with animator locker room production, the video features Marisa's escapades depicted in exaggerated, comedic sequences that align with the song's upbeat J-pop style.[24] It quickly gained traction on video-sharing platforms, amassing over 6.8 million views on YouTube alone as of 2025.[25] Another standout production, "Cirno’s Perfect Math Class" (チルノのパーフェクトさんすう教室), premiered on October 25, 2008, spotlighting the ice fairy Cirno's infamous mathematical ineptitude—often memed as "⑨" in the fandom—with lyrics poking fun at her "perfect" but absurd arithmetic lessons.[26] The video, animated by TETLA POT, employs Cirno's childlike antics and escalating chaos to match the energetic arrangement of "Beloved Tomboyish Girl," emphasizing her baka (fool) persona through visual gags like failed calculations exploding into fairy mayhem.[27] This work has similarly achieved widespread popularity, exceeding 13 million views across YouTube uploads.[28] IOSYS produced these and other flash videos using Adobe Flash software, resulting in .swf files that integrated 2D animations, character sprites, and dynamic text overlays synchronized precisely to the accompanying music tracks.[29] The visuals prioritized simplicity and humor, often reusing Touhou assets with minimalistic effects to keep focus on the lyrical comedy and rhythm. Typically lasting 3 to 5 minutes, these shorts were optimized for quick consumption and replay value.[25] Distribution occurred primarily through Nico Nico Douga, Japan's premier platform for user-generated videos at the time, where interactive bullet comments enhanced community engagement.[30]Collaborations and impact
IOSYS's flash videos have featured collaborations with external entities, most notably the 2024 parody advertisement for McDonald's Japan. This project reimagined the iconic track "Marisa Stole the Precious Thing" to promote the Samurai Mac Triple Thick Beef Burger, incorporating new lyrics focused on the product while retaining the original's energetic style. The vocals were provided by miko, a recurring contributor to IOSYS's Touhou arrangements, with updated visuals blending Touhou aesthetics with fast-food branding. The collaboration also involved Team Shanghai Alice, the developer behind the Touhou Project, highlighting IOSYS's role in bridging doujin creativity with commercial ventures.[13] These videos achieved widespread viral dissemination on platforms like Nico Nico Douga, where early uploads in the mid-2000s amassed millions of views through user remixes and shares, significantly boosting the Touhou Project's international recognition beyond Japan's doujin scene. For instance, the promotional video for "Marisa Stole the Precious Thing" emerged as one of the earliest Touhou works to gain substantial traction on the site, fostering a cycle of community interaction that amplified the series' appeal to global audiences. This online proliferation not only elevated IOSYS's profile but also underscored the videos' contribution to Touhou's expansion into mainstream otaku culture.[31][24] At doujin events such as Reitaisai and Comiket, IOSYS's flash videos functioned as key promotional tools, previewing tracks from upcoming CDs and driving sales through engaging visuals that captivated attendees. These screenings heightened fan engagement, encouraging discussions and purchases that sustained IOSYS's presence in the competitive doujin market. The videos' accessibility helped convert casual viewers into dedicated supporters, reinforcing the circle's community ties.[32] In the long term, particularly during the 2010s, IOSYS's flash videos spurred extensive fan remixes and meme creation within the Touhou fandom, influencing derivative works across online forums and video sites. Tracks like "Marisa Stole the Precious Thing" evolved into enduring memes, inspiring parodies, animations, and cultural references that perpetuated Touhou's playful themes in digital spaces. This ripple effect solidified IOSYS's legacy in shaping fan-driven content ecosystems.[24][31]Members
Music creators
IOSYS's music production is driven by a core group of creators specializing in composition, arrangement, and lyrics, often adapting themes from the Touhou Project into distinctive doujin arrangements. The team blends genres such as pop, electronic dance music, rock, and denpa-style songs, with members frequently collaborating across projects.[4] ARM, born in 1979 in Sapporo, is the founder and primary composer of IOSYS, established in 1998, where he has handled over 700 compositions and arrangements. Under the alias Armageddon Records for select releases, ARM is renowned for crafting original melodies and Touhou adaptations, including seminal tracks like "Marisa wa Taihen na Mono o Nusunde Ikimashita" (Marisa Stole the Precious Thing) and "Cirno no Pāfekuto Sansū Kyōshitsu" (Cirno's Perfect Math Class), which popularized the circle's humorous, genre-spanning style blending pop, jazz, rock, metal, and EDM. His contributions extend to anime soundtracks, such as "Dēfuragu!" (D-Frag!), and game music for titles like The Idolmaster Cinderella Girls, emphasizing catchy, versatile hooks that define IOSYS's sound.[33] Yoshimi Youno, co-founder and born in 1979 in Sapporo, serves as the lead lyricist, having penned over 400 songs with a signature humorous and playful style that infuses Touhou arrangements with witty, denpa-inspired wordplay. She also provided vocals in early IOSYS works and has produced more than 60 CD titles, including hits like "Meumue Petantan!!" that exemplify her lighthearted approach to lyrics. Youno's multifaceted role as producer, director, and engineer has shaped the circle's output, with contributions to anime like The Idolmaster Cinderella Girls ("LET’S GO HAPPY!!") and games such as Blue Archive ("Romantic Seaside").[34] D.watt, a Sapporo native and early member, specializes in electronic arrangements and club/dance music, drawing from Akihabara pop culture to create high-energy Touhou tracks that gained traction on platforms like Nico Nico Douga in the late 2000s. As composer, arranger, producer, and DJ—also working under the lyricist alias Nanajo Retasu—D.watt has contributed to IOSYS's dance-oriented releases, such as those featuring Hatsune Miku in IOSYS TRAX, and provided music for arcade games and VTuber projects.[35] Uno, known professionally as RoughSketch and born in 1987 in Hokkaido's Shibetsu Town, joined IOSYS in 2010 as a composer and arranger with expertise in vocal mixes, techno, hardcore, and dance music. His work enhances IOSYS's rhythmic complexity, appearing in Touhou arrangements and external contributions to arcade games like beatmania IIDX and SOUND VOLTEX, as well as anime such as YuruYuri; he also co-founded the IOSYS TRAX sub-label for electronic-focused tracks.[36] John=hive, from Ebetsu in Hokkaido, primarily handles lyrics but also composes and arranges with rock influences, contributing to IOSYS's more guitar-driven pieces and the virtual unit Hachigatsu Nisetsu. His thematic focus on "nighttime companionship" appears in Touhou adaptations and collaborations like "Ready Set Q!!!" for the rhythm game QQQbeats and "Walking Night" for Blue Archive, adding emotional depth to the circle's repertoire.[37] Void, whose real name is Kobayashi Yuuya and born in 1985 in Sapporo, joined in 2007 as a composer, arranger, and lyricist, known for versatile melodies ranging from high-energy denpa songs to ballads. A more recent key addition, void's standout IOSYS contributions include Touhou tracks alongside broader work like the anime opening "Daydream Syndrome" for Yumekui Merry, which charted on Oricon and Billboard, and music for KONAMI and TAITO games.[38]Other contributors
In addition to its core music creators, IOSYS relies on a network of contributors handling vocals, visual design, production logistics, and event support to bring its doujin music projects to life.[4] Key vocalists include miko, a prominent vocalist known for iconic tracks like "Cirno's Perfect Math Class" and "Marisa Stole the Precious Thing" as well as parody arrangements; Aikorin, known for guest vocal appearances; Momiji Yamamoto, a vocalist and voice actor who participates in live performances; Ayu; and Misa.[4][39][40] These performers add distinctive voices to IOSYS's Touhou-inspired tracks and original works, enhancing the circle's energetic and humorous style without overlapping into composition duties. For design and production support, the team includes contributors such as Takuya and Hakase.[4] Other roles encompass web radio hosting by members like MOC, who engage fans through online broadcasts, and doujin event staff managing booth operations and fan interactions at gatherings such as Reitaisai. Detailed profiles of these contributors are maintained on the official IOSYS website.[4][2] Since its inception as a core duo in 1998, IOSYS's contributor pool has expanded significantly by 2025 into a collaborative team of over 20 individuals, reflecting the circle's growth from independent doujin efforts to a structured production entity with broader operational needs.[2][20]Discography
Studio albums
IOSYS's entry into Touhou Project arrangements began with their early studio albums, marking a shift toward full-length releases centered on the series' music. The inaugural Touhou-focused album, Tōhō Kazakuraen ~ Phantasmagoria mystical expectation (東方風櫻宴), was released on May 21, 2006, at the third Hakurei Shrine Reitaisai event. This 11-track release primarily featured instrumental arrangements, establishing IOSYS's reputation for creative reinterpretations of ZUN's compositions.[41] Just three months later, IOSYS followed with Tōhō Otomebayashi (東方乙女囃子) on August 13, 2006, at Comiket 70. Comprising 12 tracks, including vocal and instrumental arrangements, with a total runtime of approximately 46 minutes, the album emphasized catchy, character-driven arrangements that incorporated humorous and energetic elements, solidifying IOSYS's doujin music presence.[42] In more recent years, IOSYS has explored diverse genres while maintaining their focus on cohesive full-length albums. The ongoing TOHO BOOTLEGS series has become a staple, with volumes emphasizing club and electronic "on-site" styles; notable entries include volume 8 on October 20, 2024, at Autumn Reitaisai 11, and volume 9 on May 5, 2025, at Reitaisai 22, each containing 7 tracks. Like their predecessors, these albums are event-exclusive, underscoring IOSYS's commitment to the doujin scene with innovative thematic explorations.[20][14]| Album Title | Release Date | Event | Tracks | Theme/Style |
|---|---|---|---|---|
| Tōhō Kazakuraen ~ Phantasmagoria mystical expectation | May 21, 2006 | Reitaisai 3 | 11 | Instrumental Touhou arrangements |
| Tōhō Otomebayashi | August 13, 2006 | Comiket 70 | 12 | Vocal and instrumental Touhou arrangements with energetic themes |
| TOHO BOOTLEGS Vol. 9 | May 5, 2025 | Reitaisai 22 | 7 | Club/electronic Touhou styles |