I've SOUND～Mixシリーズ～Vol.23『Close to me…』／KOTOKO × 怜奈

I've SOUND～Mixシリーズ～Vol.5『Cross talk』／Mary × 怜奈

4 ぎりギリLOVE ED「unsymmetry」【KOTOKO】Full

I've SOUND～Mixシリーズ～Vol.31『Isolation』／怜奈 × RINA

KOTOKO - Collective

I've SOUND～Mixシリーズ～Vol.34『I pray to stop my cry-White little devil mix-』／RINA × KOTOKO

[KOTOKO] I can't get over your best smile

島みやえい子　Close to me...

→unfinished→

amethyst [アメジスト] / KOTOKO 〔I've sound〕歌詞付き

Scarlett ED　「loose」

I've SOUND～Mixシリーズ～Vol.33『砂漠の雪』／MELL × IKU

I've SOUND～Mixシリーズ～Vol.7『IMMORAL』／川田まみ × KOTOKO

Tsuyokiss FE ost 18 Isolation

Snow Angel ~ KOTOKO

[KOTOKO] LOVE A RIDDLE

KOTOKO - being (Audio)

[KOTOKO] resolution of soul

KOTOKO - Trust You're Truth～明日を守る約束～

amethyst (I've sound KOTOKO)

【I've Sound】amethyst / KOTOKO