Oooh shit!!
This is accually a japanese drama I watched long ago and mistaken it for a manga >•<"
This one .. it called Yamada Tarô monogatari
https://www.google.com/search?q=Yamada+Tarô+monogatari &client=ms-android-samsung-gs-rev1&prmd=ivn&source=lnms&tbm=isch&sa=X&ved=2ahUKEwif0vmQ7vzeAhXHSxUIHcCRBAYQ_AUoAXoECAoQAQ&biw=412&bih=670&dpr=2.63#imgrc=VIU_8fGHcOzrHM
And it seems if is based on a manga of the same title~~
I just checked few chapters of it and it seems that it has few major differences..like in the manga the rich guy already knows that the poor guy is poor and the scene that i mentioned of him following him home isn't in the manga I guess.
So j would recommend the drama if anyone interested (≧∀≦)
Soo.. there this manga i read long ago but I can't remember the title of it ..someone help!!
So from what i recall it's about a super poor boy who entered a private school (was it private?? Can't say for sure) I think he entered it because of his grades blah blah blah.
So everyone in the school thinks his super rich and something and all the girls are like KYAAAA! And all that.
So the accuall rich dude in his class started to get somewhat interested in him as he noticed few things about him (like how his pencil case is a box of chocolate..etc) and he started following him secretly go his house...
Oh and by the way the poor boy house is like a size of a single room as I recall and he has like 5 younger brothers??? Maybe?? Can't recall how much were they.
I think I'm writing the whole plot now xP
Oooh and I think this manga isn't yaoi.. it's a slice of life and there is bunch of bromance.