I am looking for mangas that have either of these if possible.

a) A MC who is hated/alienated juat for the fun by others. He want to be a part of their group but is never accepted. Even afterfew years he is still alone but he is doesn't mind it until he meets new people.
I am looking something like Oregairu and an with circumstances like Hikigaya if possible. I have read and watched animes and mangas but none had this.

b) A manga where MC confess his love to his crush whom he knew from quite a time but is rejecred by her in a demeaning way. He smiles and thanks her for giving an answer but after sometime thw girls starts to miss him like he helped me with this matter that time, etc., and starts to accept her feelings for her. But it's too late as this person has moved away or they graduated from their middle school or high sschoo. But they meet again after few years but the boy says that he won't disturb her life and will remain away from her path or like.

c) The girl he falls for is from a rich family and the MC is below commoner in wealth and status. But he knows his position and never tries to crosa the boundaries of tje societies. He tries hard to be best in studies to get the scholarship from school and in future too. Then he talks with the girl for the first time as co-member of a certain club or student council and then thier story begins.

These are the few setups and if they are there I would love to read them but no yuri and yaoi.
Thank you.

Nothing available for these?

Lol, I was about to post about to Hikigaya for your first one but you obviously know that series.

For C, it's not 100% what you're describing but Bokutachi wa Benkyou ga Dekinai has the main character be pretty poor and is working to get a good scholarship to help provide for his family. The drama being he has to tutor two genius girls who want to go into the opposite field (mathematics/science into literature/humanities and vice versa). As it's kind of a harem type series (one of the assistants worked on Nisekoi), I can't say for sure who he'll ultimately fall for, but I believe at least one of the main three ladies is rich.

I hope this helps a little bit maybe?

Quote from UpToFourPlayers

Lol, I was about to post about to Hikigaya for your first one but you obviously know that series.

For C, it's not 100% what you're describing but Bokutachi wa Benkyou ga Dekinai has the main character be pretty poor and is working to get a good scholarship to help provide for his family. The dram ...

Looks like we are pretty much into same mangas.
And Hikigaya is my favourite character of all so no doubt you guessed it right.
And for the recommendation, I just read it' 17th chapter. It's good and liking all the three girlsand don't really know who to root for truly and if I had to it would the childhood friend.