Kounai Renai shitara Kubi♡

Shuuya Imari (26) works at a high school with a strict new policy: "In-school romance is forbidden—break this rule and you're fired." As a serious professional, he figures teachers shouldn't be wasting time on love when they have students to look after anyway. But his convictions are shaken when the school's new and strikingly handsome nurse, Rio Yotsuumi (22), begins pursuing him with alarming devotion!

(Source: Square Enix)