Two men working at the same company find themselves trapped in relationships that leave them starved for physical affection. Hagiwara Kazuaki lives with his long-term girlfriend Kaori, but the couple has not been intimate for nearly a year, and the growing distance between them fills him with doubt. Nakarai Sei, Hagiwara's quiet and aloof coworker, shares a home with his childhood best friend Fujisawa Kazuaki, for whom he harbors unrequited romantic feelings that his friend refuses to clearly acknowledge or reject.

One day, a misdirected email accidentally sent from Hagiwara reaches Nakarai. What begins as an awkward apology gradually transforms into an anonymous written correspondence between two strangers who have no idea they see each other every day at work. Their exchange deepens as each man confesses his private frustrations and longing for physical connection, finding comfort in the anonymity of a sympathetic listener who understands their pain without judgment.

As their emotional intimacy grows through these messages, both Hagiwara and Nakarai reach breaking points in their existing relationships. Hagiwara is forced to confront that he and Kaori may want fundamentally different futures. Nakarai discovers that Fujisawa has been keeping a secret that undermines the foundation of their fragile situation. When these two unhappy men finally learn each other's true identities as coworkers, their shared secret and accumulated longing erupt into a passionate affair that transforms the quiet drizzle of their frustrations into a torrential downpour of emotion. The story follows how two people who could not find fulfillment in the love they were supposed to want discover an unexpected outlet for their turbulent feelings in each other.

This Boys Love novel, originally published in Japan in 2013, won second place in the 2014 BL Award rankings. The rain serves as a central metaphor throughout, representing both the characters emotional isolation and the release of their repressed desires when they finally connect.