Anime where MC is betrayed by his team-mates

I am looking for an anime with this kind of a premise:

The protagonist works with a group of friends whom he really trusts. However, some of those friends come across a bigger opportunity from someone with higher authority and experience, so they end up leaving their original group, without actually informing the leader (the protagonist). (or they keep working in the new group without informing the original group). The MC learns about this and forms a new group (or goes solo) to defeat his former team members in some kind of a competition.

Example of a show with this kind of story: [Anime name]How to raise a boring girlfriend.

And yes, I don't want them to resolve this issue in any way. I am an evil-hearted person, so I want to receive immense gratification from seeing former team members suffer and feel jealous.

It can be from any genre. I just gave an example.

Please go through my MAL, then you can suggest accordingly.

Thanks a lot! :D