http://www.mangago.me/read-manga/anohito_to_nitenai_kuchibiru/ There you go! I also friggin love the yakuza story!!!!
honto yajuu
omerta kouchou no yuma not kate (end of butterfly's dream) http://www.mangago.me/read-manga/omerta_kochou_no_yume_no_kate/
there the ike reibun stuff. http://www.mangago.me/read-manga/kobi_no_kyoujin/
saki aida - http://www.mangago.me/read-manga/aiso_tsukashi/
and look at her novella http://www.mangago.me/read-manga/esu/
it's a really unique manga, there is no exact similar concept. it's easy to enumerate popular yakuza stories but Anohito is essentially different from them maybe that's why it's loved so much. These are somewhat close:
http://www.mangago.me/read-manga/koi_made_hyakurin/ (FAVE!)
http://www.mangago.me/read-manga/gun_and_heaven/
http://www.mangago.me/read-manga/hana_to_ryuu/ (be careful this will wreck your heart)
http://www.mangago.me/read-manga/yasashii_anata/ - manly couple
I read hana to ryuu just this morning....I decided to reread some of the mangas by that author since it had been a couple of years since I had read them...and completely forgot how Hana to Ryuu ended...I cried...but yea I know Anohito is a lot different than regular yakuza yaoi...probably one of my favorites.
Im looking for a yaoi where the uke and the seme have black and white snake or dragon tattoos on their back. I think they might be part of the yakuza...thats about all I remember...if someone can think of it let me know please!?!