Rio, a young office worker, suddenly finds her long friendship with Sakurai, a college buddy she never thought of as a romantic interest, turned upside down when he kisses her out of nowhere and confesses his feelings. Hesitant but drawn in by the unexpected intensity, she agrees to date him and quickly discovers a side of him she had never seen: a devoted, praise-heavy, and physically affectionate boyfriend who seems determined to adore her relentlessly. Set against the backdrop of everyday adult life in contemporary Japan—commutes, office work, late nights, and cozy at-home moments—the story follows the couple as they navigate the early thrills and deepening intimacy of a new relationship. Rio, who gradually melts under Sakurai’s constant attention, learns to let go of her reservations while he, a calm and collected salaryman, reveals an increasingly possessive and doting nature. Notable narrative arcs include their first Valentine’s Day, where a flurry of surprises and a stolen shirt leads to a playful battle of seduction; an episode where Rio tries to catch Sakurai off guard with a new pair of glasses, only to be overwhelmed by his composed reactions; the decision to move in together, which accelerates both their domestic life and physical closeness; and a trip to meet Rio’s parents, where Sakurai’s earnestness wins over a stern father, leading to a surprise marriage proposal. Later chapters focus on their one-year anniversary, with Rio hinting at a ring and the couple solidifying their commitment to a future together. Throughout the series, the central dynamic is Rio’s journey from cautious surprise to wholehearted surrender, balanced by Sakurai’s unshakable and often teasing devotion.