Shota Oni: https://www.mangago.me/read-manga/shota_oni/
Papa Wolf and the Puppy: https://www.mangago.me/read-manga/papa_wolf_and_the_puppy/
Polarity: https://www.mangago.me/read-manga/polarity/
Tougen Anki:
https://www.mangago.me/read-manga/tougen_anki/
Kemono Jihen: https://www.mangago.me/read-manga/kemono_jihen/
* I don't think these have romance
Eleceed
rental onii chan
Must read this webtoon
Recommend me literally anything without romance