Wow! This thread has been going for a few years now. The battle to lose weight or to keep the weight off is one I have been fighting for years myself. It is about 80% diet ( not dieting but diet. As in food you eat and not counting calories etc. ) and the remaining 20% exercise. I lost 25 pounds ( 11 kilos) by simply following these points.
#1. Not eating after 7:00PM. For me anyway, food I ate after 7:00PM or so was never burned off since I was usually home and in and relaxing at this time. That food would be turned into fat since I wasn't burning it off.
#2. Instead of taking the bus/train to work ( I live in Kawasaki Japan by the way ), I started commuting by bicycle. It didn't make sense to try to get to a gym after work since that was taking extra time out of my free time. I had to travel back home from work anyway so I would use that commute time for exercise. One day a week I would run home from work so only on run days would I take the bus/train one way.
I have been able to keep this up since 2008 and have kept the weight off. So try at least #1 above for starters and you'll see a difference I feel. Good luck all!