Super no Ura de Yani Suu Futari

Sasaki, an overworked salaryman, goes through an average stressful day just for a single light at the end of the tunnel: Yamada, the always-cheerful clerk at his favorite convenience store.

One day, Sasaki takes an extra amount of time at a company meeting, and by the time he gets to the convenience store Yamada has already clocked out. However, as he leaves, he notices a young woman with piercings smoking behind the store?

Links:

• Alternative Official English - Manga UP!