Kaoru Mitsuya is twenty-one years old and his life has already reached a dead end. Ensnared by organized crime from a young age, he has just been released from prison after taking the fall for his former gang's higher-ups, leaving him with no money and nowhere to go. While wandering the streets, he is beaten up by thugs and collapses in an alley, resigned to his fate. At his lowest point, he discovers a strikingly beautiful person lying unconscious on a bed of scattered rose petals. Believing them to be a woman, Kaoru offers his help and learns that the person is Yuichiro Shirouzu, a twenty-nine-year-old man who runs a small flower shop in the entertainment district.

Despite his shock at the revelation, Kaoru accepts Yuichiro's unexpected offer of a job and a place to live. Yuichiro, whose delicate appearance hides a surprisingly pragmatic and kind nature, runs a nighttime florist that caters to hostess clubs, entertainers, and even the yakuza. Kaoru soon discovers that his new employer suffers from a weak constitution, often collapsing from exhaustion or illness such as anemia and asthma, which explains his need for an assistant. As Kaoru settles into his new life, learning the language of flowers and the rhythm of the night shift, he begins to feel the first stirrings of genuine affection and protectiveness toward the man who saved him.

The story tracks Kaoru's gradual transformation from a hardened former criminal into a devoted, if awkwardly flustered, employee and potential suitor. The narrative is a blend of slice-of-life comedy and gentle romantic tension, fueled by Kaoru's constant "gay panic" as he navigates his growing feelings for Yuichiro. This domesticity is complicated by the intrusion of Kaoru's past, as well as the appearance of supporting characters who add pressure to the relationship. These include Kaoru's younger brother, Ryo, a police officer who is wary of his brother's past, and Yuichiro's own family, including a twin sibling whose arrival causes a mistaken identity crisis for Kaoru.

As the first volume progresses, the romantic stakes rise. Kaoru is forced to confront his jealousy when Yuichiro receives a dinner invitation from the underboss of the Aosaki gang, placing him in proximity to the very world Kaoru is trying to escape. Later, the shop is attacked by thugs, forcing Kaoru and Yuichiro to fight side-by-side, which deepens their reliance on each other. Set against the backdrop of neon-lit streets and the quiet, fragrant sanctuary of the flower shop, Kaoru’s journey becomes one of redemption and self-discovery, as he learns that his life might not be over and that he might be worthy of the care and affection offered by the mysterious florist.