Okane ganai?
Something like that
I have a thing for this kind of plot (≧∀≦)
more funny ones
http://www.mangago.me/read-manga/datte_ai_ja_nai/
http://www.mangago.me/read-manga/hisho_ikuseichuu/
more... porny?
http://www.mangago.me/read-manga/kawaii_obaka_kun/ though not yakuza
uke has no depts but needs money and seme is yakuza boss soooo I thought...
http://www.mangago.me/read-manga/gokudou_darling/ (btw. love it)
(っ´ω`)ノ(╥ω╥) I feel with you!
if you dont want exactly yakuza and dept I collected some around this theme (money). the list is still small (too lazy lately and I dont like too big lists). so when you are bored http://www.mangago.me/home/mangalist/82294/
Does anyone know any yakuza manta where the uke has to pay back large sums of money