Los Blancos coach Santiago Solari was expected to make a few changes, but it wasn't the case at all as the big guns were all unleashed. Gareth Bale and Karim Benzema started in attack alongside Lucas Vazquez, with Ballon d'Or winner Luka Modric slotted in the middle of the park.
Kashima nearly took the lead inside two minutes as Serginho tried his luck from the left side of the penalty area, but it was superbly tipped behind by Thibaut Courtois.
A ball played through by Modric to Benzema presented the Frenchman with the opportunity to break the deadlock, but his effort was straight to Kwuon Suntae, who collected at the second attempt.
Bale followed suit to try and open the deadlock, but his long range shot glided well off target.
On the stroke of half-time, Los Blancos were ahead after good work from Marcelo set up Bale for a clinical first-time finish.
Real made it two shortly after the break when Bale was in the perfect place to pounce following poor defending where he placed the ball in an empty net.
Modric and Marcelo then combined to set up a pass to Bale who completed a stunning hat-trick in the space of 11 minutes.
Solari then removed Bale for Marco Asensio with the game firmly in control for the European champions.
Vazquez missed the opportunity to make it four after being in the position to lob Suntae, but his final delivery lacked the desired power.
The Japanese champions reduced the deficit with 12 minutes to go after a corner from Yasushi Endo found Shoma Doi who headed past Courtois.
Isco set up Benzema to kill off the match in the closing stages, but he shot wide from close range as Real settled for a 3-1 victory to set up a final meeting with Al Ain on Saturday.