I am searching for a yaoi manga in which the uke or seme is a bit of yandere. Know any? I ...

These?
http://www.mangago.me/read-manga/totally_captivated/
http://www.mangago.me/read-manga/kawaii_akuma/ (Try some of his other works?)
http://www.mangago.me/read-manga/dou_imo_nara_nai/

You rock! Million thanks, friend.

yandere uke part 1 in ch.8:
http://www.mangago.me/read-manga/star_na_koi/
part 2 in ch.3:
http://www.mangago.me/read-manga/star_ni_ai/

http://www.mangago.me/read-manga/hitomi_no_honne/
http://www.mangago.me/read-manga/hitomi_no_giwaku/ sequel
http://www.mangago.me/read-manga/kaihatsu_muramura_mode/ ch.4
http://www.mangago.me/read-manga/akutai_wa_toiki_to_mazariau/
http://www.mangago.me/read-manga/sokubaku_kei_kareshi_boyfriend_restraint_system_free_dj/
http://www.mangago.me/read-manga/ikusen_no_toki_o_koete/

+ most of Fujisaki Kou`s mangas:
http://www.mangago.me/home/mangalist/7543/

Enjoy ! huehueheue ლ(´ڡ`ლ)