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)
YANDERE/POSSESSIVE
- http://www.mangago.zone/read-manga/kusatta_rasen/
- http://www.mangago.zone/read-manga/hikizuru_oto/
- http://www.mangago.zone/read-manga/imitation_mate/
- http://www.mangago.zone/read-manga/mujintou_ni_motte_iku_nara/
- http://www.mangago.zone/read-manga/stalker_s_game/
- http://www.mangago.zone/read-manga/deichuu_no_hasu/
- http://www.mangago.zone/read-manga/obey_me/
- http://www.mangago.zone/read-manga/ibitsu_no_kakera/
- http://www.mangago.zone/read-manga/yami_bl/
- Ch5: http://www.mangago.zone/read-manga/kanchigai_lokidoki_koi/
- http://www.mangago.zone/read-manga/individual_diet_preference/
- http://www.mangago.zone/read-manga/poison_and_sex/
i tagged these mangas as 'psychological' and 'twisted' which may or may not have a yandere character, but the overall theme and ambiance are similar
Can someone recommend anything that has yandere or yakuza vibes