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 E231-3000 Series was introduced in 2017 to replace the older (but not much) stock on the Kawagoe and Hachiko Lines. They were converted from Chuo-Sobu Line E231-0s, wich are being displaced by former Yamanote Line E231-500s (themselves displaced by the E235). They entered service on the 19th of February 2018.
Currently there are six 4-car sets in service, all based at Kawagoe Depot.
Similarily, a few Chuo-Sobu Line 209-500 Series sets were also converted into 209-3500 Series trains for use on the same Kawagoe and Hachiko Lines.