A while back, I remember reading this yaoi manga that was set in a boarding school of some sort in the future. Everyone had different castes (?) and the guys would be paired off in a master x servant sort of relationship. There were a bunch of different couples and the chapters alternated focusing on the different couples.

One of the couples that stood out was the seme guy with black hair and all "cool". Though it's eventually revealed that he's extremely extravagantly silly. He was sorta childish too. And the servant guy was this loud outspoken one who did not want to be a part of this. Of course, the seme guy ends up falling in love with him, much to the other guy's chagrin haha, and a ton of hijincks ensues. The seme guy also uses a chain around the servant guy's neck too.

There was one scene where the extravagant seme guy wanted to have a date with him and ended up waiting for hours in the rain, since the servant guy didn't show up and was eating with his friends in a restaurant. The servant guy eventually saw him waiting and ran to him. This servant guy also liked this other girl and kept her necklace for a long time, which was eventually thrown into a pool in another scene.

I'm just focusing on one couple, because that's the one I semi-remember most! I know this was a horrible way of explaining it, but this is all I can recall. I'd greatly appreciate it if someone could help me find this manga! Thank you so much

Is it Ai to Yokubou wa Gakuen De?

Omg yes it is! I have no idea how you were able to figure it out
Thank you so much!!