Osananajimi no Mama ja Iya?

Osananajimi no Mama ja Iya? (幼なじみのママじゃイヤ?, You Don't Want a Childhood Friend as Your Mom?) is a manga series written and illustrated by Tsumikidou.

Plot
People often say that falling in love is a wonderful thing, but what if the one you fall in love with wants to be your mom?

A story about a boy who agreed to his childhood friend's proposition of becoming his "mom". He thought they were playing house, but she meant it for real.

Official

 * https://seiga.nicovideo.jp/comic/43356