Koisuru Tsubaki wa Shoya ni Saki

Tsubaki Takeda grew up in her grandmother's flower shop after her parents passed away. They've always relied on business from the famous flower-arranging Shinomiya family, but when the Shinomiyas started buying flowers elsewhere, Takeda's flower shop fell in danger of closing. That was when the head of the Shinomiya family visited them, and offered to buy flowers from the Takedas again, if Tsubaki will agree to marry their younger son Ren. A marriage of first-loves that grew from a contract between a poor flower girl and the flower-arranging scion of a prominent family.