In some countries, you could get your Bachelors by 21 and finish your PsyD or PhD by 25. There may be a few tests and hoops to jump through, but that's all you really need to be a psychologist. The 10 additional years may help for some countries or specializations, but in the US, you could get your license and throw out a shingle by 25--especially if you finished college or your Phd early.
So I googled Japanese psychologist requirements and it turns out most people practice after getting a Masters in Japan--so if he started his undergrad at 18, he could be done by 21 and started working as a psychologist at 23.
https://www.apa.org/international/pi/2007/05/japan.aspx
http://www.megurocounseling.com/psychologist_in_japan.html
Ah, I was too lazy to google it out to be sure xD. Thanks!
It did seem to be that way :). Such things really differ between countries huh.
That's why when people change countries sometimes their permit gets refused and they'd have to go back to study again just because the requirements aren't exactly the same.
But I guess that means it'd make more sense that he's a psychologist then! I'll have to look up raws someday aha.

Does anyone know for certain? Is he a psychiatrist, a medical doctor who can prescribe meds etc.? Or is he a psychologist, a specialist who is licensed to do talk therapy?