The third and fourth from the top. Natalie is leading an exercise class and the next one in a restaurant. And in the club is there a rank above Bar Master?
You haven't met Serena then? She's at the town bar during week nights. If she's not appearing, you might need to start a clean game as something's bugged :/ Her questline will unlock researching new stuff for the club and school.
The exercise class is a special scene you get if you turn down Nanako when she's doing the health checkup on you. The restaurant part happens in the intro if you choose the "sub route".
