She was not one of the original players and only tagged along to be with Yuu whom she seems to have a crush on. She gets jealous when other girls are friendly with him. As the horror that develops she is constantly seeking reassurance and protection from Yuu. She is the daughter of a cop which contributes to her strong sense of morality and her mother died when she was young. Yuu found her crying and promised to protect her and they have been close since. She is the most emotional of all with a weak constitution screaming or fainting at the first sign of danger or injury. Mitsuki wants to believe in the good of everyone in the group giving everyone the benefit of the doubt and she tries to do the right thing even under the deadly circumstances. Her barcode was on her neck.