Japan was of no challenge to Brazil as Makoto Teguramori's side went down 2-0 at the hands of Neymar & Co. in its final Rio Olympic warm-up on Saturday.
Brazil cantered to a win behind first-half goals from Gabriel Barbosa and Marquinhos ahead of its opening Olympic Group A game against South Africa on Thursday.
Japan, eyeing its first medal since Mexico 1968, launches its sixth successive Olympic campaign against Nigeria in Group B in Manaus, also on Thursday.