recommend

Several popped in my head but the first was
https://www.mangago.zone/read-manga/haou_airen/
Haou Airen - don’t really remember the plot but someone brought it up today

https://www.mangago.zone/read-manga/raise_wa_tanin_ga_ii/
Then Raise wa Tanin ga Ii

https://www.mangago.zone/read-manga/gokusen/
Gokuen


Police x Gang member
https://www.mangago.zone/read-manga/what_i_decided_to_die_for/
What I Decided to Die For

https://www.mangago.zone/read-manga/raise_wa_tanin_ga_ii/

Minus police

yakuza like a dragon