BAKEMONOGATARI GN VOL 15 (C: 0-1-1)

One day, high-school student Koyomi Araragi catches a girl named Hitagi Senjougahara when she trips. But - much to his surprise - she doesn't weigh anything. At all. She says an encounter with a so-called 'crab' took away all her weight... Monsters have been here since the beginning. Always. Everywhere.