On March 15, JR East will introduce the limited express "Shonan" (weekday AM and PM peak service only) between Odawara and Tokyo/Shinjuku, using refurbished e257 stock. These will replace 185 series and 215 series stock used in the various existing "Shonan Liner" services, which will be discontinued. There will be a total of 10 "up" services each weekday, and 11 "down" services. Trains will be 9 car consists, with the exception of three services in each direction having 14 cars.
timetable:
https://www.jreast.co.jp/ltd_exp/tokaido/pdf/pdf_202103timetable.pdf
Ayokoi video of the 185 and 215 series on the liner services at Odawara: