Kobayashi Mizuki

 (小林瑞希) is a member of Sekaicity and a former member of EAT IN, SiAM&POPTUNe, and Frappe idol Project Kenshuusei.

In March 2017, she was promoted from Frappe idol Project Kenshuusei to SiAM&POPTUNe.

SiAM&POPTUNe stopped activities in December 2017 and she officially left the group in November 2018.

In December 2021 she debuted as a founding member of EAT IN.

She was transferred to sister group Sekaicity on September 16, 2022.