Office romances are not uncommon, and there is a serious reason for that, as people who see each other day after day establish a certain emotional closeness, which in turn can lead to a physical relationship. It so happens that Masuga and Yui work in the same office and succumb to the influence of their feelings. Their mutual sympathy is evident, and they behave very tactfully, not trying to force anything. They are satisfied with exchanging tender glances and having casual conversations on topics unrelated to work. From the outside, they seem like just colleagues who have developed a friendly relationship.
Both are afraid to cross the line and, most importantly, to reveal the truth about how they feel about each other. They think it is best not to violate professional ethics and to hide the fact that they have managed to fall in love. However, love cannot fit within strict boundaries and only intensifies, making it increasingly difficult for the guy and the girl to behave reservedly, like spies behind enemy lines. Eventually, some of their colleagues begin to notice that something is off with this couple. They start paying closer attention to them, causing the protagonists to behave tensely and give away the true state of affairs.