The 2014 World Cup hosts never needed to get out of second gear in Poland, as they picked up another convincing friendly win against the Samurai Blues
Paulinho opened the scoring in the 12th minute with a 20-yard drive, before a Neymar penalty doubled the Selecao's advantage just before half an hour.
The Santos forward made it 3-0 minutes into the second half, before a late Kaka goal put the icing on the cake of a match where Brazil never looked like losing their nerve.
Kaka started again in what was a virtually unchanged lineup for Mano Menezes, who made only one change from the 6-0 win over Iraq, with Leandro Castan replacing the injured Marcelo.
Alberto Zaccheroni followed suit, swapping a single player from his side’s 1-0 triumph against France, as Keisuke Honda was restored to the starting XI in place of Mike Havenaar.
It was the Asian side who threatened first, as a one-two between Shinji Kagawa and Kengo Nakamura saw the latter test Diego Alves with a drive from the edge of the area.
Brazil, though, quickly got into their stride, and found themselves in front with 12 minutes gone. Oscar advanced deep into the opposition half and laid off to Paulinho, who arrowed a low shot into the bottom corner from 20 yards out.
The Corinthians midfielder could have had another minutes later when he latched onto Neymar’s glorious feed, but after rounding Eiji Kawashima, could only steer his finish wide of the far post.
Brazil would get their second though, after a dubious penalty was awarded for a challenge by Yasuyuki Konno on Kaka. Neymar stepped up to bury with confidence from 12 yards out.
The Selecao continued to flow on the counterattack, and a threaded pass from Kaka released Neymar on the run, but the Santos prodigy could only lash over the bar from close range just past the half hour mark.
Makoto Hasebe then nearly responded in kind, as he forced a good save out of Alves with a well-struck effort from just outside the area.
But Brazil were soon back down the other end of the pitch, Hulk freeing Neymar brilliantly, who in turn teed up Kaka on the edge of the box for a shot that ricocheted off the woodwork.
The match was ended as a contest three minutes into the second half, as Neymar was able to beat Yuto Nagatomo to the ball on a corner and drive in his second goal via a huge deflection off a Japanese leg.
Kagawa could have given Japan a glimmer of hope shortly after the restart with a mazy run into the Brazil box, but after doing so well to evade multiple defenders, he lashed his shot the wrong side of the post.
Brazil came close to another through Hulk, who blasted in a 20-yard free kick that took a deflection off a defender before cannoning back off the base of the post.
The South Americans then put the ball into the back of the net for a fourth time as Ramires turned home Neymar’s cross, but the goal was incorrectly chalked off after the officials had mistakenly adjudged the ball to have crossed the byeline before Neymar’s delivery.
There were no such doubts about Kaka in the 76th minute though, as the Real Madrid midfielder turned his marker on the run and slotted a confident finish past Kawashima after being set in motion by Hulk’s pass.
By that point, Brazil were probing leisurely in the Japanese half to close out the victory in control, with even substitute Lucas Moura missing a late chance for a fifth.