Man, this show's been prooving to be awesome every week.
Starting by the episode titles, it always foreshadows what is about to come. The theme this week was about trades and bargains, and we clearly see everyone trying to acquire an upper hand through this. Getting old tests, buying off points, giving class notes.

In regards to the MC, it's awfully clever of him trying to get the attention to other people. He just got Horikita some friends, which might get him on her good side and eventually make it easier to manipulate. He gave Kushida the credits for the test sheet, all the while avoding mentioning he had a part if not all the credit for it.
It's easier to maneuver when all the attention is diverted somewhere else.
You have no prying eyes, so less chance of getting caught doing whatever it is you're doing. It's pretty clever. It also keeps expectations off of him, so no one gets disappointed if he fails, and everyone gets surprised if he succeeds, his chances being increased since no one is suspecting.

Kushida turned out like expected, and she was doing just fine except for her mistake of making sure no one was following her. So now, MC has something on her, and she won't be able to get things from him that easily and she'll be stepping on eggs around him.

I hope the novels get translated soon!