Ren Yamai is a secondary character in Komi Can't Communicate. She has a perverted obsession towards her former classmate, Komi Shouko, acting as her personal stalker who is willing to do anything to keep Shouko for herself. Underneath her cute facade, Yamai is obsessed with Komi to a disturbing degree, ranging from stalking her to lustfully licking a strand of her hair. She has been described as a yandere. Ren even has a collection of pictures of Komi in her room. In her introductory arc, Ren resents Tadano for befriending Komi with little effort and kidnaps him, believing that she was doing Komi a favor due to viewing him as completely average. However, this ends up blowing up in her face when she saw that the opposite happened with Komi wordlessly telling her that she would decide on her friends herself. After the incident, Yamai tones herself down instead of resorting to situations where she could act pervertedly around Komi. One instance is when she attended the summer festival and wanted Komi to kneel down so she could take a bite from her sausage only for that to be thwarted by Najimi.