what is necessary for teaching in japan?

hello, iam 25 years old my nationality is korean but iam currently in australia now but i met my wife here and she is pregnant, she also wants to live in japan. So i told my wife i would get a tesol cert. and teach in japan. I have researched many sites but i still just cant be sure of what i must do. everyone tells me different things. I want to know which tesol cert or diploma is good to get a teaching job in japan also would they hire an asian person to teach english to japanese people? my english is perfect because i grew up in america. Is it possible i can get a job in japan? If it is please teach me how its very urgent ;(

• Japan