Satou-san, a middle-class officer worker, is a senpai to Yano-san, a reserved and quiet office worker. His relationship with the silent Yano-san is not bad, but not good either, it's a very vague relationship... One day, Satou-san happened to enter a con café and met a maid named "Hina". He heard this voice, her atmosphere, this... somewhere before. He can't believe it! Senpai and kouhai by day. By night, maid and master. This exciting and healing work comedy about two people who have a mysterious relationship! (MTL)