Hi everyone

I will be flying in to Narita from Singapore on UA late Dec (arrived at 2:45pm). I will spend a night at Yugawara (ootaki hotel) and then spend rest of the time in Tokyo Ikebukuro area. Normally I am a carry-on only person but I will be out 3 weeks this time so I expect to have at least 1 check bag for this trip. I am looking for suggestion as to what is the best/efficent way to deal with my check bag(s) and to get to Yugawara before 7pm possibly.

Using Jorudan I found the following options.
Option 1: Take N'Ex to Shinagawa, store my bags in the 500yen locker and take Shinkansen to Odawara and JR Tokaido to Yukawara.
Option 2: Take N'Ex to Tokyo, store my bags in the 500yen locker and take Shinkansen to Odawara and JR Tokaido to Yukawara.
Option 3: Ship my bags to my hotel from Narita, I will be staying at B Ikebukuro the following nights.
My main concern is finding 500yen coin locker at either Tokyo or Shinagawa station. Also, is it reasonable to think I can catch the 3:45pm N'Ex based on my arrival time and to get N'Ex ticket/ arrange bag delivery service? I will be in C and by the exit so I should be one of the first to deplane.

Any suggestions is appreciated.