Ichigo Ouji

Crumb, the royal Strawberry Prince from the stars, comes down to Earth in search of a bride in a form of a Strawberry Daifuku. Then comes along Sato Hazime, a glasses wearing 24 year old, who buys a box of daifuku from a store. Following that night unknowingly taking a bite of a "special" daifuku, Sato releases the Strawberry Prince. The next morning Sato awakes with proposal from Crumb along with an engagement ring in a shape of a strawberry (of course!). (Source: Shinshokan, translated)