Appears in the Shinobu/Sakura arc. Sakura is Shinobu's friend and obtains the notebook from Keiko, a girl in another class. She is eager to hunt down a mermaid and eat her flesh, but won't divulge the name of whom she likes. Sakura obtains the notebook and additiona information from Nanae, deliberately keeping it from Shinobu. She believes that her crush, Yamaguchi, is in love with Shinobu, when actually it's Sakura whom he's in love with — however, the realization comes too late and the jealous mermaids drag her with them before dawn. Eventually, Sakura captures an unassuming Yamaguchi and kills him, his blood enabling her to take human form. However, it's evident that she's not the same as her old self, as she doesn't respond to others. Shinobu theorizes that Sakura was moved to kill Yamaguchi after seeing him with Mana. Sakura is later returned to normal after Shinobu confronts Q, though as per the lore she is still not fully human.