Mana receives a heartless message on RAIN from her classmate, Karin. The next day, her friend Miyabi suggests that she use the Curse App to get revenge, and soon installs the app to Mana's phone. Without taking it too seriously, Mana enters Karin's name into the app. Karin later posts on INSTE about getting injured. She receives an eerie notification on the Curse App that read, "Enter a name in three hours or the curse will rebound to you."
The Curse App spread instantly, and the amount of victims increased. Numerous strings of hair grew out of Mana's phone and reached out for her... can Mana sever the chain of curses!?