Monogatari

When high school student Koyomi Araragi rescues fellow student Hitagi Senjyogahara from a fall down the stairs, he realises that she is impossibly light and wants to know more about her.

Hitagi and Koyomi turn to the crab god who took not only Hitagi's weight, but also the painful memories of her mother, which she now wants to process and carry herself.

Koyomi finds a disoriented girl named Mayoi at the playground. When he offers to help her, she rejects and offends him.

When Koyomi and Mayoi talk, he learns that she is on the way to visit her mother, but can't find the house. The spirit of a stray snail seems to be at fault.

Koyomi learns that Mayoi has been dead for a long time and is only seen by those with a subconscious desire not to return home. They finally find the address of Mayoi's mother.

Koyomi meets fellow student Suruga, and discovers she was once best friends with Hitagi, but they had a falling out. On his way home, Koyomi is attacked and injured.