Bakemonogatari (Manga), volume 4

From the best selling novel series by renouned author NISIOISIN, comes the manga adaptation of the Monogatari Series!
Artwork by Oh! great.
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.