Kurai Hana has drifted through school like a ghost since childhood, invisible and friendless — until she crashes into a girl named Delena and, over four months of conversation, finds herself coming alive. When she witnesses other students bullying Delena, something shifts in Kurai Hana. Now she has a new goal: remove every person making Delena's life difficult, one by one, until nothing stands between her and the moment she can finally confess.