Consists of a volume with various oneshots. Hattori's in love with his best friend Kameda but shuts out his feelings because he doesn't want to destroy their friendship. But what happens to the lock he put on his heart when a girl Kameda likes makes an appearance...?! Aside from "Kagi - Key" this book also contains the one shots "Alkaloid", "Breath", "Night, Midnight" and "Dogs and Summer Clothes".