I have read once this manga but I can't find it now. All I remember is:

Uke is a runaway or he doesn't have a place to go and seme take him in. They happily live together but one day seme comes home and he finds uke with another man. But it's just a misunderstanding because they did nothing. Seme gets really angry and he kicks out uke from the apartman. And the uke cries that he has nowhere else to go and beg to let him in back.

It was a heartbreaking scene for me and if I remember correctly seme doesn't take back uke right away, and uke keeps wondering in the town alone. But I'm not sure.

It's not Not/Love

Suki Toiunoni Nazekashira ch4?

Hmmm no, it's not 🙁 but thanks 🙂

The summit, maybe?

Could it be Name of Love http://www.mangaupdates.com/series.html?id=11343 ?

Come to think of it though Not/Love may be what I'm looking for. 😀 😀 😀 😀 But thank you guys for the suggestions I will read them!