Shuudengo, Capsule Hotel de, Joushi ni Binetsu Utawaru Yoru.

The manga centers on Minori, an office worker, and her boss Hadano, who are constantly arguing with each other. One night, after a company drinking party, Minori and Hatano are having their usual argument, when Minori realizes that she has missed the last train. They decide to spend the night at a nearby capsule hotel, but an incident forces them to share the same unit.
(Source: Anime News Network)