|Series:||AKB48 Murder Mystery|
|First Appearance:||Uchida Mayumi Testimony File|
|Last Appearance:||Uchida Mayumi Testimony File|
|Number of Episode|
|1 (Testimony File Only)|
- "Renacchi, Yuko-chan, then Mayuyu. When our chance came, it was great, but if it's our turn to be killed next, it is horrible. Our turn… Speaking of which, is there any meaning in the turn in which they were being killed?"
- ―Uchida Mayumi's Testimony[Testimonials and Alibis (src)]
Uchida Mayumi (内田眞由美?), nicknamed Ucchii (ウッチー?) and Mayuchi (まゆち?) is a member of AKB48's Team K. She is one of the primary characters in AKB48 Murder Mystery series. She was based on and was portrayed by Uchida Mayumi.
All 89 members of AKB48 went to a duplex island owned by one of Akimoto Yasushi's friends for a CM Shoot. After their first day shoot was over, they went to their designated resthouse on the other island. It was assumed that she heard that Kato Rena was missing and was shocked to learn that the scream they heard was from Sashiko finding the girl's lifeless body in the dining hall.