The midfielder lined up on the right of a front three, with world's most expensive player Neymar on the opposite flank and Gabriel Jesus positioned through the middle.
Neymar opened the scoring from the penalty spot after just 10 minutes, taking advantage of a VAR system decision for the award of foul, but was denied a second from 12 yards shortly afterwards when Eiji Kawashima saved.
Marcelo did, however, add second minutes later, firing a thundering effort into the top left-hand corner from 25 yards.
It was 3-0 before half-time when Willian fed Danilo on the right who, in turn, found Jesus unmarked at the back post to slot home.
Japan netted a consolation after the break, Tomoaki Makino heading in Yosuke Ideguchi's free-kick delivery before Willian was withdrawn on 71 minutes.
Liverpool's Philippe Coutinho is Brazil head coach Tito's first choice on the right flank, but Willian was afforded the chance to impress as skipper in France.
