thats a long name... and it is not that new. The Metropolitan New Urban Railway has been operated the Tsukuba Express (line) since 2005. Thing that is (sort of) new is the TX-3000 series, which is operated since 2020.

why the whole line is called express? the main reason is rapid (express?) train is operated frequently on the route (2 per hours) , and the whole track is designed for high speed operation of a 130 km/h. This is thanks putting the track on bridge and underground to avoid road crossing. With ATO (automatic train operation) system, the line allows high frequency train service. Also, the gap between each station is pretty far, so you can imagine that train can be operated without stopping for a while

As a side note, between Moriya and Miraidaira there is a neutral zone to allow transmission of AC and DC zone, which is (very) rare for a private railway. DC is used between Akihabara and Moriya because of law requiring commuter railroad in Tokyo to use DC. On the other hand, AC is used between Miraidaira and Tskuba is to avoid intervention with Meteorological Agency Magnetic Observatory.

TX-2000 series

speaking of which, they are operated under one man per driver mode. i heard JR east is consider such practise for some route.

and i hope federation problem go away