This is a reskin of the E231-500 Series made by Rizky_Adiputra and avaible on his website (jirctrainz.com).
All the necessary dependencies are included in this .rar, included in the original content’s package or avaible on the DLS.
The introduction of the E235 Series on the Yamanote Line in 2015 led to a cascade-replacement of rolling stock on most of JR East’s Tokyo network lines.
The surplus E231-0 Series sets from the Chuo-Sobu Line were reformed into 8-car sets and moved to the Musashino Line starting from 2017, with the aim of replacing the last remaining 205-0 and 205-5000 Series (205s refurbished with IGBT-VVVF inverters) sets.
At present there are five sets in service on the line, with more to come.