Yotsuba, a married woman working at a gyudon chain restaurant, becomes close with her college student coworker. Yotsuba is drawn to the earnest and sincere young man. One day, because they had the same commuting time, they went out for drinks and ended up having a relationship. Even after work or during breaks inside the store, and even in the kitchen while in operation, they would do it anywhere, realizing that their bodies were perfectly compatible...
