Responses
I'd like to know too. :)
http://www.mangago.me/read-manga/okane_ga_nai/ is the first one that crosses my mind. ლ(´ڡ`ლ)
http://www.mangago.me/read-manga/aijin/ this one would probably the closest to the description (I didn't read Kimi no Ondo though)
http://www.mangago.me/read-manga/suki_ni_naccha_ikenai_hito/
http://www.mangago.me/read-manga/love_home/ (maybe? I don't really remember it too well)
Any yaoi like http://www.mangago.me/read-manga/kimi_no_ondo/ with very poor family and the bro who sell himself for buy food ect or something like this???