A couple of posts ago I mentioned that we had used the JR Nambu line for part of our day trip to Ome in June of last year. We rode between Musashi-Kosugi and Tachikawa but this line is actually part of an outer loop line around the Tokyo area. We had used this line a few times before and have noticed newer and newer trains assigned to this line over the years.
Tokyo Railway Labyrinth blog.
So on the last day we were in Tokyo I visited a few of the shops in Akihabra. Kato had recently released a model of this train and it was in stock in several shops so I was able to shop for the best price.