Comment by qiqitori

That's nitpicking, IMO. It's still 99% true. There are just two "Mini-Shinkansen" lines, they only run once or twice per hour, are shorter than non-Mini-Shinkansen, and only a relatively short part (distance-wise) of their journey is spent on the slow tracks. There are non-Shinkansen trains on the Mini-Shinkansen portion of their journey, but not very many. (Also the word "shinkansen" implies new tracks.)