Ore ga Onna ni Shite yaru yo: Toshiue Kareshi wa, Uete Ookami ni naru?

A 10-year age gap! Her doting boyfriend's first serious love turns her into a "woman"!?

Miharu moves in with a male relative after starting university. She expects him to be a tired, workaholic uncle, but 28-year-old Tatsuhiro is a friendly, experienced, and handsome man!? She's been carefree and relying on him like an older brother, but one day something happens that makes her see him as a "man"—. "Aren't you going to run away...?" Held tightly from behind by his large, cigarette-scented body, her whole body melts at the sight of Tatsuhiro's aroused side, which she's never seen before... A sweet and steamy age-gap doting love story ♡

(Source: Overlap, translated)