Well I can't use that excuse as I don't live in Japan. I've gotten unhealthy in my own damn house in my own damn country. I became something of a workaholic this year due to expanding, and I think that's the main factor in my decline in health. Not that I was particularly health conscious before either, which makes it worse. Blood pressure has shot up, weight shot up... just fucking bad all around. Gotta turn it around before it's too late.
Well, the main thing is to find something that's motivating, and then no matter what you do, get into it slowly or you'll hurt yourself.
When I quit smoking and decided to get in shape I was 26 and had never jogged in my life (unless running from the cops in high school counts). I found a pair of Nike's at some stupid shopping mall in Osaka, put them on and started jogging (probably at something embarrassing, like 15:00/mile pace). I made it about a block, or roughly one minute, before I thought I was going to suffocate and have a heart attack and that was my first workout. The next day my entire body hurt and my lungs were still burning. But you'd be surprised how quickly the body can heal itself and adapt. Within a couple weeks that 1 minute jog turned into 5, then 10 minutes the next month. About a few months in I stunned myself by running a 10:00 mile. By the end of the year I was running three or four consecutive miles at 8:00/mile pace. And then a few years later the federal government really turned me into the athlete I wasn't meant to be (I was running a 5k in the morning in around 20 minutes, and that was my "easy day" workout), but that's a long time ago.
And it's during my time with the federal government that I saw the consequences of trying to do too much, too fast. I'd get young guys, Army paratroopers and Rangers, show up at some of our fitness exams and had never prepared for the exact type of intense exercises and tests we were running. Cocky young shits might run 6-mile formation runs every other day and stick their dicks in the vaginas of five continents but still weren't prepared to do what we were doing. I saw guys rupture tendons, tear hamstrings, black out unconscious and occasionally even require a trip to the emergency room. So whatever you do, start off slow.
But in the end, you need to nail down what motivates you. For me, it's my vanity, pure and simple. I like looking the mirror and being impressed with myself. Yes, that may be a sign of something very wrong with me but at least I'm honest with myself. Whenever I start thinking about skipping a workout, I just imagine not fitting my tailored suit anymore...and then drag my ass out the door and run.
And even on those days where I've got a six or seven mile jog planned around the shoreline or boulevard, and I'm in the "fuck this shit, I'll do it tomorrow" mood, I think of the other thing that motivates me to hit the road: the female joggers. I fucking love the body of a woman runner...those long, lean bodies, nice perky little tits all wrapped up in sports bras with their nipples poking out, tight asses and thighs with beautiful tans and their hair done up in a ponytail. I can jog behind a hot female running for miles, and runners have a sort of code, where that's not weird or scary because we're all runners, and runners don't do creepy shit to each other. Little do those women know that not only am I staring at their asses and enjoying it very much, but sometimes when I need to turn up the speed and clock some faster intervals, I channel my inner rapist and pretend I'm chasing the bitch down. I catch up to her, but pass her, put about a quarter mile between us then take it easy for a bit and let her catch up, then do it all over again. I did that once with a group of girls from the high school cross country team and felt a little bad about it, until their coach (who was insanely hot) instructed them to catch and pass me. I have far too much pride to be beaten by some teenage girls, so I turned on the afterburners for about a mile and left those bitches way back in the dust...then collapsed at the park behind some bushes where hot coach and her stupid team couldn't see me. What can I say? Vanity.
Find something that motivates you and go with it.