Tonari ni Sumu Oshiego to Kekkon Shitai no desuga, Doushitara OK ga Morae Masu ka?

I began living by myself ever since I entered high school, and all of a sudden, my teacher Ms. Mitsuki proposed to me. Her hairstyle and clothing are different, but could it be that… she’s the woman living next door who I have a crush on!? But, how can we marry with this age gap! Even so, we began to date (tentatively)… “Pass me your keys. I’ll go make a duplicate.” “Huh!” Whether day or night, she barges in my apartment from next door, and flirts with me relentlessly in school whenever there’s a chance to! The girls in my class even almost found out about it—Ms. Mitsuki, are you serious about marrying me!? The love comedy of a beautiful and older teacher who lives next door and her student begins!

(Source: Overlap, translated)