https://www.mangago.me/read-manga/shokuryou_jinrui/
https://www.mangago.me/read-manga/alive/
https://www.mangago.me/read-manga/enjokousai_bokumetsu_undou/
https://www.mangago.me/read-manga/kami_no_kodomo/
https://www.mangago.me/read-manga/biomega/
https://www.mangago.me/read-manga/helter_skelter/
https://www.mangago.me/read-manga/save_me/
i like these, but i'm sure you can find many more if you cross out romance and such, and seinen manga tend to be more complex pol-wise while josei are more drama heavy, so maybe something like this: https://www.mangago.me/genre/Seinen/?f=1&o=0&e=Yaoi,Doujinshi,Shounen%20Ai,Yuri,Romance,Smut,Ecchi,Shoujo%20Ai
Please give me some good manga which have NO romance. And have an excellent plot.