How long do people stay?

I went to Okinawa 2 months ago and saw a really cute guy working at a burger place at American village (forgot the restaurant name but I know I can find it again with this picture I took). He was slightly muscular, mustache, brown hair, maybe American I’m not sure.

I wanted to ask for his number but I was leaving to Korea the next day since I’m a student here. I’ve never asked for someone’s number before as well so lots of nerves.

Anyways I keep thinking of him and I really want to go back to Okinawa and find him again. I have personal study and work plans which would allow me to stay in Okinawa for few months if necessary. I just wasn’t sure if it was worth it to go back to Okinawa next month (the closest possible time for me) since it’s winter and ofc I don’t know if he would be there. I would go next summer but that’s a long time and perhaps he would be long gone. I really don’t know much about Okinawa or even Japan but my 2 precious trips in Japan were some of the most memorable experiences and I would really like to stay for several months anyways.

Any advice or opinions?