Urooboe Uroboros!

Urooboe Uroboros! (うろおぼえウロボロス！) is a one-shot manga chapter by Nisio Isin with illustrations by Takeshi Obata. It was serialized in Weekly Shonen Jump.

Plot
Two weeks after Kakizaki had transferred schools he is confronted by the eldest of the Harimoto Sisters and is 'told' to go out with her younger sister.