Kiyosumi Serika

Serika is introduced as Miyu's best friend and a rather enthusiastic admirer of Kanna.
An active, energetic and compulsive girl, Serika is a member of the Megurimiya Academy's tennis club. While most of her screen time is spent following, harassing, and making passes at Kanna, she also holds Takahisa in high regard, and has taken to calling him "ani"; one could say that Serika considers herself Takahisa's surrogate younger sister next to Miyu.