My Boyfriend Is a Big Baby

Childhood friends Ao and Ritsu attend the same university. Though Ritsu is the older of the two, he operates at 110% stupidity, so it's younger but more put-together Ao who has always been the one looking after his hot mess of a best friend. Today, Ritsu once again comes over to Ao's place unannounced and drinks himself stupid(er), leaving Ritsu to help him into bed. But this time Ritsu, in his drunken fervor, makes a sudden left turn in the conversation and jumpstarts an unexpected development in their relationship...!

(Source: MangaPlaza)