What do you think of my plan :D?

Well, I think it's a little odd that you want a guy since it doesn't really seem like you two have talked a lot BUT....having said that, if you make friends with this guy who has a genuine interest in you (after getting to know you!) to get closer to the handsome boy, it IS a bit manipulative. I think you should do it, but don't neglect your brother's friend's companionship once you get what you want. Then that's just using him.