-OutsideR:RequieM- is the third solo song for Naru Hakobe (箱部なる), a character from Sega's Irodorimidori (イロドリミドリ) multimedia project, voiced by M・A・O. The track was composed and arranged by Ryouta Suemasu of Elements Garden, with lyrics by Asuka Oda and a music video directed by MiRA. It first appeared in CHUNITHM STAR on January 25, 2018, before crossing over to maimai FiNALE on March 8, 2019. In maimai it was initially categorized as an Original song before being moved to the オンゲキ＆CHUNITHM genre with the でらっくす PLUS update, reflecting its origins in Sega's other rhythm game franchises. Musically, the song is a driving rock piece built around its BPM of 181, with aggressive guitar work and propulsive percussion that mirror the lyrical themes of defiance and rebellion. The title's stylized wordplay, pairing "OutsideR" (outsider) with "RequieM" (requiem), signals the narrator's embrace of an outlaw identity. The lyrics weave battle imagery and confrontational language, with recurring phrases centered on struggle, judgment, and uncompromising self-assertion. The full version, along with an instrumental arrangement, appears on the third Irodorimidori album 卒業 (Sotsugyou). In maimai, the song offers four standard charts ranging from Basic (level 4) to Master (level 13+), with the Master chart designed by Jack and the Expert chart by はっぴー (Happy). The Master chart is noted for its dense Slide-note patterns, packing 130 Slide notes into its 817-note total.