| Year | Song(s) | Album | Ref. |
|---|
| 2000 | "Prime" (with Aki) | Dear Feeling | |
| "Sora Yori Chikai Yume" (Second Track) | |
| "Ashita no Mukō" | |
| 2002 | "Namida no Chikai" (Album mix) | Disintegration | |
| "Flow: Mizu no Umareta Basho" | |
| "I Can't Get Over Your Best Smile" | |
| "Resolution of Soul" | |
| "Wing my Way" (Album mix) | |
| "Kimi yo, Yasashii Kaze ni Nare" | |
| "Dirty Boots" (as Outer) | Dirty Gift | |
| "Ano Hi no Kimi e" | Onegai Teacher 2nd Vocal Album - Stokesia | |
| "Snow Angel" | |
| "Amethyst" | Tsumamix Vocal Collection | |
| 2003 | "Face of Fact" | Lament | |
| "Save Your Heart" (Album mix) (with Kaori Utatsuki) | |
| "Kageri" (Album mix) | |
| "Feel in tears" | |
| "Natsukusa no Senro" (with Kaori Utatsuki) | |
| "Lament" | |
| "Heart of Hearts" | Outflow | |
| "Close to me..." | |
| "Sensitive" | |
| "Change My Style: Anata no Konomi no Watashi ni " | Short Circuit | |
| "Ren'ai Chu!" (Remix) (with Kaori Utatsuki) | |
| "Sakuranbo Kiss: Bakuhatsu Damo n" | |
| "You're My Treasure" (Remix) (with Aki and Rimikka) | |
| "Achichina Natsu no Monogatari" | |
| "Magical Sweetie" | |
| "Cream+Mint" | |
| "Omoide wa Kaze no Naka de..." | |
| "Short Circuit" | |
| 2004 | "Namida no Chikai" (the divine pledge of tears) | I've Remix Style Mixed Up | |
| "Boundary Line" | Silent Half Special CD | |
| 2005 | "Abyss" | Collective | |
| "We Survive" | |
| "Lupe" | |
| "Imaginary Affair" | |
| "Trust You're Truth: Ashita o mamoru yakusoku" | |
| "Collective" | |
| 2006 | "Allegretto: Sora to Kimi" | Kono Aozora ni Yakusoku o Special CD | |
| 2007 | "Nee, ...Shiyō yo!" | Short Circuit II | |
| "Seishun Rocket" | |
| "Princess Bride!" | |
| "Atarashii Koi no Katachi" (Short Circuit Edit) | |
| "Mighty Heart: Aru Hi no Kenka, Itsu mo no Koigokoro" | |
| "Hajimemashite, Koi" | |
| "Otomegokoro tasu Nekomimi no Heihōkon wa Mugen" (with Eiko Shimamiya) | |
| "Kyururun Kiss de Jumbo" | |
| "Princess Brave!" | |
| "Maple Syrup" | |
| "Double Harmonize Shock!!" (with Kaori Utatsuki) | |
| "Synthetic Organism" (as Outer) | I've Mania Tracks Vol.1 | |
| "Hallucino" (Remix) | |
| "Time Heals All Sorrows" | |
| "L.A.M Laze and Meditation" (2001 P.V Long Arrange Mix) (as Outer) | |
| "Crossed Destiny" | |
| "Philosophy" (Proto type Mix) | |
| "Leave Me Hell Alone" (as Outer) | |
| 2008 | "Suppuration -core-" (G.M.S. remix) | Master Groove Circle | |
| "Real Onigokko" (Ben Watkins from Juno Reactor remix) | |
| "Re-sublimity" (Shiva Joerg & Hard Stuff remix) | |
| "Uzu-maki" (Eat Static remix) | |
| "Kisetsu no Shizuku" | The Front Line Covers | |
| "Belvedia" | |
| 2009 | "Ha!!!ppiness" (as Outer) | I’ve Mania Tracks Vol. II | |
| "Prime: "Thank you" and "From now"" | |
| "Absurd" | |
| "Yakusoku" | |
| "Cave" | |
| "Fatally" | |
| "Seishun Rocket" (Short Circuit II Edit) (with Kaori Utatsuki) | |
| "Akanezora: Sore ga Bokura no Sekai Datta" | Maji de Watashi ni Koi Shinasai! Special CD | |
| 2010 | "Blossomdays" | Short Circuit III | |
| "Raspberry" | |
| "Crash Course: Koi no Tokubetsu Lesson" (with Kaori Utatsuki) | |
| "I need magic: Tokenai Maji Kyun" | |
| "Omamagoto" | |
| "Stars Biscuit" | |
| "Swift Love: Kenzen Danshi ni Monomōsu" | |
| "Lilies line" | |
| "Yumemishi Boom! Boom!" | |
| "Jōshiki! Butler Kōshinkyoku" | |
| "Hoshizora Interceptor" (with Kaori Utatsuki) | |
| "La clef: Meikyū no Kagi" | Extract | |
| "Restoration: Chinmoku no Sora" | |
| "A Piacere" | |
| "Oblivion" | |
| "Jihad" | |
| "Leaf Ticket" | |
| "Ketsudan no Entrance" | |
| "Onaji Sora no Shita de" | |
| "Gensō no Prism" | |
| "Hallucino" | |
| "Undying Love" | |
| "Cross Up" | I've Mania Tracks Vol. III | |
| "Loose" | |
| "I Pray to Stop My Cry" | |
| "Gensō no Prism" | Prism Magical Special CD | |
| 2011 | "Fly to the Top" | Tribal Link | |
| "Immoral" | |
| 2012 | "U Make Ai Dream" | Level Octave | |
| "Genzai no Requiem" (Album mix) | |
| "Bloom" | |
| "Presto" | |
| "U" | Comic Market CD 83 | |
| "Wing of Zero" | |
| 2013 | "Kirameku Otome" | 'Nekoneko Soft' Soshite Kirameku Otome to Himitsu 5 Special CD | |
| 2014 | "Wing of Zero" | Evidence Nine | |
| "Reboot On/↓0" | |
| "Soupir D'Ange" | |
| "Love Mission!!: Nanda. Tada no Koi ka" | |
| 2016 | "Stardust Train" | The Time: 12 Colors | |
| 2017 | "Sign of Suspicion" | Alive | |
| "Imaginary Affair" (2017 Version) | |
| 2018 | "Erika" (with Tatsh) | War of Brains Original Soundtrack | |
| "Instincts Answer" | ave;new Concept Mini Album Labyrinthine Nerve |
| 2022 | "INTERNET OVERDOSE" (with Aiobahn) | NEEDY GIRL OVERDOSE official soundtrack | |
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