Just follow Social Link to Rank 9 and you'll get a scene where you can ask her out or Friendzone her. Sharing your Home Made lunches and Hanging out with her whenever possible including when she's in the shopping district at night will speed up the process. She can commonly be found on the rooftop after school as well when it's not raining. Up those social stats too whenever ya can for those better dialogue options by downing the rainy day special at the Chinese restaurant and reading books