Amagai Kosame (雨谷 小雨, Kosame Amagai) is a newly introduced character in Shoujo Site|Mahou Shoujo Site. She was shown saving Shioi Rina, Aya Asagiri, and Tsuyuno Yatsumura in chapter 20 of the series. It is later revealed that her Mahou Shoujo Stick is a small blade, which she uses to cut her wrists with frequently. Upon cutting herself with her stick, she can then use her blood to heal her comrades if needed. However, she is unable to prolong the lifespan of others.
In her introduction, she explains that she was recruited by a different Mahou Shoujo Site, other than the one the main four characters were recruited by. What her life before her recruitment as a Mahou Shoujo is currently unknown.