Mina Tatebayashi  

, 館林 水奈

Mina is a unique being who possesses both mermaid and vampire characteristics. At five years old, she is under the guardianship of Shidou following an unfortunate incident that occurred shortly after her birth. Unlike her twin sister Kana, Mina's blood type more closely resembles that of a mermaid, which causes her body to grow into a teenager's size when submerged in water (with larger breasts, as depicted in the anime). Additionally, Mina is known for being quite vocal and impulsive in her speech, using the Kansai dialect.