What do you think is going through the mind of a guy who suggested exchanging LINE contacts at the first meeting, then repeatedly reads my messages without replying? I feel so uncomfortable and really regret exchanging contact information with him.

Maezawa here—I’ll answer too. I don’t know whether there’s any particular reason they keep leaving your messages on read, but if you’re sending them as questions and still being ignored, it’s understandable that you’d feel dissatisfied. If your messages weren’t phrased as questions, why not try sending one that is easy to answer? If you still don’t get a reply after waiting a few days, I don’t think you need to regret anything. You can just block them. Also, I looked into it and apparently some Android phones mark messages as read just from displaying the notification, even if the person hasn’t actually opened them. Either way, no reply is still no reply, but it might be worth knowing that messages can sometimes be marked as read even when they haven’t been viewed. That would be different if they had an iPhone.