Saeko Matsushita’s husband returns home early alongside a much younger and handsome coworker. Since they have time to spare, they all 3 have dinner together.
They have some friendly drinks but as Saeko cannot handle alcohol she ends getting drunk easily and kisses the coworker mistaking him for the husband.
Moreover, encouraged by the husband, the coworker ends up sleeping over at their house.
The next morning. The husband is gone to Osaka because he has an urgent work meeting, for 3 days straight… So Saeko and the coworker find themselves having breakfast alone…