When heading to JR Osaka Station(JR大阪駅) from JR Kitashinchi Station(JR北新地駅), it is convenient to use West Gate (西口改札) of JR Kitashinchi Station.
It takes about 12 minutes from West Gate of JR Kitashinchi Station to JR Osaka Station.
More details will be explained later.
Osaka Station Map

Transfer at JR Kitashinchi Station to JR Osaka Station
The details are as follows:

After getting out of West Gate of JR kitashinchi Station, follow the JR Osaka Station sign.



You will see Circular Plaza (円形広場)of Diamor Osaka in front of the passageway.
Crossing Circular Plaza, keep going straight.


Passing in front of Department Store Gate of Hanshin Osaka-Umeda Station, keep going straight.


Passing Daimaru Department Store, go upstairs using the escalator in front.

Go about 50 meters, and you will see Central Gate of JR Osaka Station on the left side.