Responses
the rich guy- do you remember if he was the (supposted to be) seme or uke?
Seme i think (althought most of it is plot and i don't really remember it they even fuck once.)
dont think its this but lets give it a try:
here its like this. though not primary but middleschool classmates http://www.mangago.zone/read-manga/soine_lovers/uu/soine_lovers-chapter-2/24/
Read shounen ai/yaoi a long time ago and cant find it :( its about rich man who has found his poor classmate from primary school. In exchange for money he makes him a personal slave for a week. (Nothing sexual/no rape)