So, yes I did go to Tokyo to run a marathon and my luck with the weather continued. That is, lack of luck. The two days before the marathon were perfect race conditions, cloudy and temperatures around 10-15C (50-60F). However, race morning everything changed and it ended up being 23C (72F), sunny and WINDY! The course is an out and back basically in a straight line. This straight line ended up being into the wind for the first half. Not the greatest. As a result I thought I was running conservatively in the first half but I think I was running harder than I realized. Once I made the turn at halfway I picked it up for a little bit but it didn't last as my stomach started cramping at around 26km and I ended up stopping at 30km. Of course, as with everything at this race even dropping out was organized. I was escorted on to the "scoop bus" given a blanket, a towel, water and some strange coffee candy. I had to wait for a while until the 30k cut-off time was reached and those that didn't make it joined me on the bus for a slow return trip to the stadium.
The race organizer was very nice about everything and seemed keen for me to come back next year and give it another chance. The Japanese always polite still gave us a few more gifts after the race!