My guess is her friend in Hokkaido wanted to talk about who they have crushes on, girl talk since I bet the friend is a girl, and Hokkaido girl reacted in some way to the fact that our girl said she didn’t like anyone, perhaps thinking they weren’t close enough for her to share/that she’s lying, or a joke about how childish/naive our girl is with a bit of bite. She is asking if he likes anyone because she’s looking to gauge how normal it is to have someone like that in mind, that you always watch. Which is funny, since he’s been watching her and little else even though it’s the school trip. He’ll end up being honest I bet and talk about how he doesn’t really know what it is to like someone that way.