Ok so you want to open an account in Japan.
About 20 online discount brokers are listed here if you could read Japanese.
http://www.hikaku.com/sec/
But one thing you have to know first that you have to be resident of Japan.
I didn’t check every one of them but most of them have that rule.
As to Japanese stocks, I haven’t followed them anymore.
I could find few chat groups in Japan if you are interested.
I wish I could help you more.
BTW "The daily trading coach" is a good read.
GLTY