Oh I LOVE when semes go down on their ukes too! Kinda frustrating that it's almost always the reverse with only or almost only ukes who go down. But here are some favourites where the storyline and characters are good too! ٩(๑❛ᴗ❛๑)۶
http://www.mangago.zone/read-manga/warehouse/
a few really good ones (chapter 7, 49, 52)
http://www.mangago.zone/read-manga/bbanana_scandal/
first season, another couple second season with only the uke going down so far
http://www.mangago.zone/read-manga/a_proxy_painter/
Seme goes down a lot, the uke's dick is tiny though
http://www.mangago.zone/read-manga/the_place_where_the_wind_blows/
Looked at the raws and may change in future chapters though (but amazing seme on uke scenes so far)
http://www.mangago.zone/read-manga/legs_which_cannot_walk/
Especially second season, the seme gets some kind of "drinking uke's milk" fetish haha
http://www.mangago.zone/read-manga/rv/
Most of her other stories too
Where the seme goes down on the uke. (〜 ̄△ ̄)〜