[kael]

Having dealt with something like this before, I have to say - it sucks, but you're going to want to be there. Hopefully things will turn out okay and your dad will be fine, but if they don't... trading away a year or so of your life in tokyo is a tough decision, I'm sure, but I personally value every last minute I had with my father before he passed on.

You've got plenty of years ahead of you, so I'd say spending one helping take care of your parents isn't a bad idea. You'll be glad you did afterward, if it means that you have more good memories of him to look back on and you were able to say goodbye without leaving things unresolved.

For now I'd try not to worry about it, but if it looks like things are going bad for your father, I'd at least make preparations to be able to leave. Even if you haven't decided yet, the more notice your friends, coworkers and loved ones in Tokyo have before you leave, the more chance that you'll be on good terms with them in a year or two if you decide to come back and pick things back up where you left off.

Dealing with parents you're not on good terms with is always a struggle in this sort of situation, but even if you and your mother aren't on good terms, she'll appreciate having you around.

I hope things work out okay for your parents.