I would have taken the eye compliment as a yellow flag and appreciated it as a genuine compliment with no ulterior motives. I think the shoulder massage offer is where I’d draw the line and say, yes that’s clearly someone looking to escalate things physically with you rather quickly.

At least in my culture that would be seen as strange between acquaintances and still pretty strange between friends. I don’t think Japan is different in this regard so I would recommend clarifying your intentions sooner rather than later.

You originally brought up your virginity and your long term desires for sharing that with a long term partner. I would not bring that up with anyone you didn’t want to convince you out of that belief. That might not be anyone’s individual intention but that’s the worst case scenario so you should consider it. That means telling a best friend is probably great and would be recommended. Telling an acquaintance or a friend who is also sexually attracted to you - and therefore may not be the best councilor to you for purely your benefit - would probably be an unwise thing to do. Unless of course you want them to convince you out of that belief so that you can more casually have sex, which is fine as long as you’re being honest with yourself on who is really responsible for that change.