On the day after the Golden Week holiday, third year high school student Koyomi Araragi finds himself saving a classmate, Hitagi Senjyogahara, by catching her when she slips on the stairs and comes tumbling down from above. He discovers that she's impossibly light, as if she has no physical weight whatsoever….

On the day after the Golden Week holiday, third year high school student Koyomi Araragi finds himself saving a classmate, Hitagi Senjyogahara, by catching her when she slips on the stairs and comes tumbling down from above. He discovers that she's impossibly light, as if she has no physical weight whatsoever….

Koyomi meets Mayoi Hachikuji, an elementary school girl who is frantically comparing the town map displayed in the park to the memo in her hand. Learning that Mayoi has lost her way en route to a relative's home, Koyomi offers to help, only to be violently rebuffed.

Koyomi meets Mayoi Hachikuji, an elementary school girl who is frantically comparing the town map displayed in the park to the memo in her hand. Learning that Mayoi has lost her way en route to a relative's home, Koyomi offers to help, only to be violently rebuffed.

Koyomi meets Mayoi Hachikuji, an elementary school girl who is frantically comparing the town map displayed in the park to the memo in her hand. Learning that Mayoi has lost her way en route to a relative's home, Koyomi offers to help, only to be violently rebuffed.

Suruga Kanbaru, the school’s biggest star who has led the underwhelming girls’ basketball team to the national championships, begins to inexplicably stalk her upperclassman, Koyomi Araragi. When Hitagi Senjyogahara hears about this, she reveals that back in middle school, she was once so close to Suruga that they were known as the "Valhalla Combo."