Otsuki Riko

 (大槻りこ) is a Japanese idol, a member of Eisei to Karatea, and a former member of PiiiiiiiN.

She joined PiiiiiiiN in August 2019, and graduated on August 8, 2020, where the group disbanded.

She was first revealed as a member of Eisei To Karatea on June 23, 2021, although the group was founded on June 17, 2021.