On the Keihin-Tōhoku Line, Rapid trains
skip Nippori Station.
If you take a Rapid train
from Kannai or Yokohama
to Ueno on the Keihin-Tōhoku Line (Track 1),
you can make a quick transfer via the same platform
to the Yamanote Line (counterclockwise) (Track 2)
and then take a Local train for several minutes to Nippori.
Ueno Station of JR can be a labyrinth;
it sounds better to take a simpler route.
Uco:
most trains from Kannai will take you straight to Nippori It depends on time zones whether they skip Nippori or make a stop there.
Trains for Ōmiya or Urawa
which depart from Kannai or Yokohama
from around 9:45 to around 14:00
are Rapid trains, which skip Nippori;
the other trains for Ōmiya or Urawa are Local trains.
(guest):
1. Take taxis from your hotel to Yokohama Station 2. From Yokohama Station, take the JR Tokkaido Line to Ueno 3. From Ueno, take the JR Joban Line to Nippori 4. From Nippori, take the Keisei Line to Ohanajaya That requires changing platforms at Ueno,
which is not necessary in the above-mentioned transfer.
Taking a Tōkaidō Line train from Yokohama,
you may go a little faster until Shinagawa;
at Shinagawa,
you can make a transfer
to the Yamanote Line (counterclockwise) (Track 1) ;
you change platforms here.
At Nippori, you can get through the JR - Keisei transfer gate.
Only Local trains make a stop at Ohanajaya.
For Yokohama sightseeing,
Sakuragichō Station
(between Kannai and Yokohama Stations)
sounds convenient.
- Yokohama Akai Kutsu loop sightseeing bus
https://www.yokohamajapan.com/information/getting-around-yokohama/akai...Enjoy your trip!