Aooo (あうー) are a Japanese rock band formed in 2023. The group is comprised of former Idol Resistance and Akai Kouen member Riko Ishino (石野理子) on vocals and guitar, bassist Hikaru Yamamoto (やまもとひかる), and vocaloid producers Surii (すりぃ) and Tsumiki (ツミキ) on guitar and drums respectively. The band's name refers to the four members' different blood types. Their debut self-titled album was released in October 2024.