Volume 1 of the Yuu Watase Masterpiece Collection.

1. Gomen Asobase! (ごめん遊ばせ！)
Miyagawa Hao has just come to Tokyo from Osaka. To relieve her of a headache, a passing bishounen offers her a packet, which was suppose to have a pill inside. By mistake, the guy gives Miyagawa a very important button. Miyagawa finds out he goes...