Zenbu Hatsukoi no Sei da

Rei, a university librarian, is on the hunt for a marriage partner! In order to reassure her grandparents who raised her, she is looking for a suitable husband based on "attributes" alone, hoping to settle down as a “married couple." Then one day, Rei suddenly receives a public confession from Suwa, a college boy. Suwa is a transfer student with a straightforward personality, but of course he is much too young and totally out of the question! But he won't give up so easily…?

(Source: Shogakukan, translated)