hi! if u don’t mind a list try this:
http://www.mangago.zone/home/mangalist/889350/
MAFIA
http://www.mangago.zone/read-manga/you_re_my_loveprize_in_viewfinder/
http://www.mangago.zone/read-manga/dispar_4u/
http://www.mangago.zone/read-manga/yondaime_ooyamato_tatsuyuki/
http://www.mangago.zone/read-manga/mitsumei/
http://www.mangago.zone/read-manga/saezuru_tori_wa_habatakanai/
http://www.mangago.zone/read-manga/burns/
http://www.mangago.zone/read-manga/madman_combo/
http://www.mangago.zone/read-manga/seduction_against_seduction/
http://www.mangago.zone/read-manga/gangsta/ (not yaoi)
http://www.mangago.zone/read-manga/gray_lujun_kazekaoru/
http://www.mangago.zone/read-manga/totally_captivated_dj_mr_sangchuls_diary/
http://www.mangago.zone/read-manga/circle_trap/
http://www.mangago.zone/read-manga/legs_which_cannot_walk/?ov8I
http://www.mangago.zone/read-manga/kobi_no_kyoujin/
http://www.mangago.zone/read-manga/cover_up/
http://www.mangago.zone/read-manga/trap_city/ (MUST READ)
Do any of y’all know any good mafia or yakuza mangas