Responses
you mean something like this --> http://www.mangago.me/read-manga/one_fourth_mentaiko/
Yes! send me recs plz i've read this one already :/
sorry, that's also the only one I know. I guess this can fit too --> http://www.mangago.me/read-manga/free_dj_can_haruka_have_sex_with_rin_after_suddenly_turning_into_an_odd_little_lifeform/
with one character is very tiny and they have sex with the normal sized one. Prefer Yaoi but anything is fine