Just to be clear, I'm not against the MC becoming part of the DIK fraternity, I'm just saying that it doesn't necessarily have to happen this early.
Yes, the game is called "Being a DIK", but it doesn't mean you have to be part of the fraternity for the majority of the game, especially when the MC doesn't seem to want it that much. Having him go on a journey in this story where he really learns the value of being part of the fraternity and actually wants it would make it so much more rewarding.
"Being a DIK" could also be a metaphorical title, where it's not so much about joining a fraternity frivolously, but understanding what it means to be part of a brotherhood and finding your place in it, thus giving that jacket much greater symbolism.
If we get it in ep 5, fine, I've got no problem with that, but not getting in wouldn't be the end of the world especially if it becomes something that's more meaningful as the game progresses.