Although for clarification. To be eligible for a CIR position you must possess functional knowledge of Japanese language.
Also there are only 7 places a year for the SEA position, and one must have high experience of either being a National Athlete recognised abilities & recommendations nationally in their own country and should also have either a certificate in coaching from a recognised college or at least 3 years coaching experience.
The ALT positions are more straight forward in terms of requirements compared to the CIR & SEA though. All you need is to have a Bachelors Degree in anything and be enthusiastic (also do not need to know the Japanese language)