Rizelmine

Iwaki Tomonori is a typical 15-year-old boy with a preference for older women. He has a crush on his teacher but is devastated when he finds out she's engaged. Returning home heartbroken, he discovers a 12-year-old girl named Rizel waiting for him-his new wife, forced into marriage by the Japanese government. To his shock, Rizel isn’t an ordinary girl; she’s a biochemically engineered human. Her creators, whom she calls her "papa"s, offer to clear Iwaki’s family’s debts in exchange for letting her stay with them. With no choice in the matter, Iwaki’s unusual life with Rizel begins.