One day when Mashiro flunks a test in school, she decides to run away from home. If only her bad test grade could be wiped from her parents' memories? As she fantasizes about the impossible, a girl in an eyepatch and a neon pink hoodie pops up out of nowhere with a suitcase in tow. This strange girl vanishes just as quickly as she appears, and she leaves behind a small box and a black book full of bizarre products: an Instant Grim Reaper, a Friend Raffle, an Execution Kit--and a Memory Erase Button?! Just what are all these freaky items, and are they even safe for Mashiro to use? There's only one way to find out-if she dares!