In Koi Kaze, Saeki Koushirou works as a wedding planner, arranging ceremonies that celebrate commitment while his own love life remains in shambles. Recently dumped by his girlfriend, he finds it difficult to give himself wholeheartedly to love, a hesitation rooted in his family history. The child of a divorced couple, Koushirou lives with his father and has spent years separated from his mother and younger sister, leaving old absences and unresolved emotions quietly shaping the way he relates to other people.
That fragile balance is shaken after a chance encounter with a female high school student awakens feelings he did not expect. The moment becomes far more troubling when Koushirou learns that the girl is actually his sister, Nanoka Kohinata, who will now be staying with him and his father. As the siblings begin sharing a home after years apart, ordinary family life turns painfully complicated. Koi Kaze centers its drama on the collision between long-buried loneliness, sudden intimacy, and emotions that neither fit easily into the roles Koushirou and Nanoka are supposed to inhabit.
