OMG, you are asking the wrong person. In the 1st place, he isn't in thailand. And he only use thailand to mask his sinkie comments. Who knows he ask you to takeover an agogo bar he is working in. :p
If you want to start a business, getting those which are already established may be easier for you.
www.sunbeltasia.com
If you are looking for visa issues, work permit allotment,
www.thaivisa.com
They have tonnes of visa applications, see the one which is suitable for you. And steer clear of tonychat, he will brain fry you. :p
btw, why don't stay in outer parts of Japan which is near to sea, instead of going Koh Samui? Koh Samui is quite a commercial island and it gets stale like staying in Bangkok or like what you said stale in Tokyo