The menus and gashapon are a little clunky. Trying to dress the guys and understand what you actually own after drawing the clothes is frustrating. It isn't a good system. But you can earn a bunch of coins each day and turn them into tickets, and then more tickets by finishing chapters with a high enough approval rating. (That approval rating is based on the clothes the guys are wearing.)
Just know you're going to have to be patient to get all the steamy scenes. It's so rare that we get M/17+ games for women that are actually THIS erotic, so I'm content to stick with it.