is there a way to get intimacy with a school character faster? I've been grinding to get to 10% and it seems to take forever
Depends on your stats and what "path" you took at the beginning. The girls have preferences. If you're a Intimate/Hentai, it's going to take longer when you're aiming for girls who like Reserved/Kind. Lower charisma makes gaining slower. What's your charm skill lvl?
For the girls in your class, choose to socialize in class. For most every other girl, choose to socialize at the pool. Talk and hang out with them in between classes. Keep hugging to a minimal of once per day. If they approach you and ask your type, choose an answer that fit them. For neighbor, gyaru and clusmy girl tutor them after school. For sister and otaku, help swim.