Hello, my name is Tuomas Pääkkönen and this is my submission for the FKT of the Yamathon - walking route.
To begin with, there are a few things which differ from the first FKT: the route was run outside of the official competition and due to that, not all rules (e.g. the selfies at each station, run as a team) were totally followed. However, for the rest (visiting every station, at least close enough to see the sign and choosing any route consisting of public roads), the attempt should be fine. The route was ran clockwise and was based on a previous GPX found online, but adapted on the spot due to some imprecisions. Due to the unofficial nature of the attempt, it took place in February instead of October, with way colder conditions, but also snow, which brought its own set of challenges. Last but not least, I finished the loop between Shibuya and Harajuku stations at 38.3km, but kept going as my personal challenge was to make it full marathon distance, in my timing I thus considered the elapsed time, but removing the km segment times for the last 3.2km, slightly rounding up the overall distance (elapsed time 3:49:39 - 4:42 - 3:51 - 3:58 - 1:14 = 3:35:54).
The attempt was something I had had in mind for some time, but as I am not based in Japan, participating to the official race or even having much choice for the date were kind of out of question. I had ridden the line all the way around during previous Tokyo visits and having run metro lines in other cities, this challenge seemed particularly appealing to me. Due to a quite tight schedule, I had reserved only that weekend as potential dates for a run and due to the dreadful snow storm on Sunday morning, I had to push back and start around noon instead.
Not really equipped for snowy conditions, I figured out that as convenience stores would be open and provide enough supplies for the run, I packed really lightly, apart from an extra layer of clothes, and I was basically carrying a water bottle most of the time in my hands. Some parts of the course, especially stairs, were quite slippery, adding to the challenge, but due to mild conditions in the afternoon and an efficient snow removal by the city of Tokyo, most parts of the course were quite easy to run despite all that.
There were no major breaks during the attempt, but I got lost a few times due to the GPX not containing information about the latest closed roads (and thus the new alternatives), the convenience store visits were pretty quick but still added a few minutes here and there. Due to the attempt taking place on a Sunday, some streets were quite crowded and thus forced my to relax the pace a bit, even having to walk a few sections, especially around Ueno station.
I believe that this attempt is still far from what a more experienced urban trail runner/marathoner could do, especially if they manage to do it during a weekday with less crowds, and better weather conditions (neither 30 degrees nor snowy conditions are obviously ideal performance-wise).