Jin and Akitaka are coworkers, best friends, and have been roommates for ten years. Having recently acknowledged their feelings for each other, they are now happily in love and continuing their同居 life together. This peaceful routine is interrupted when Akitaka is sent away on a month-long business trip. It is the first time they have lived apart since meeting, and both struggle with anxiety and a growing longing for one another.

While lost on his business trip, Akitaka is helped by a friendly young man with whom he immediately bonds over shared hobbies. This man turns out to be Jin’s younger brother, Umi. However, when Umi directly asks Akitaka about the nature of his relationship with Jin, Akitaka finds himself at a loss for how to answer. This encounter places a hidden strain on the couple as they navigate this new challenge to their relationship. The story is a sequel that continues the warm and slightly exciting step-up romance between an easygoing, junior-type boy and a cool, hidden-dom boyfriend.