Board Thread:Love Live! School Idol Festival Lounge/@comment-6062841-20180725205628

I just got this game, and at the very start of it during setting my account up, I was given a list of 18 main leader girls to choose from. 9 of them were Aquos, the other 9 were u's. I chose Riko, but now, I want Ruby as the main leader and person to play the game with. I cant access the choice of girls now, after I chose Riko. What do I do? 