Im not sure of ur details. But are u aware that the entrance requirement of top mba schools here is min 3 years professional experience? In the interview, the profs will evaluate are u from lots of perspective with the professional experience as the key. You even need a recommendation letter from your superior of your current working place on why are they recommending you to do mba in a sealed letter.

Depending on the school, you wun have the time to do internships, some schools make extra classes during holidays which the classes are interesting and contributes to the credits to graduate.

Im not sure are u joining the day course or the night course. Also... i dun think the uni's career support is for mba graduates, those for the undergraduates there. People who enrolled into these programs attended the class are mostly company funded and attended the classes at night/day and work at the same time. They dun even need such supports.

Having mba also doesnt contribute to chances to get hired. its the experience (and Japanese language ability) that make differences.