Japan interim coach Mark Hammett limited the changes ahead of Saturday's second test against Scotland, making just two to the side that started last week's 26-13 defeat.
Male Sa'u, who is returning from injury, was handed the No. 14 jersey (rather than his more favored No. 13) and Rikiya Matsuda was named at fullback for the game at Ajinomoto Stadium.
Sa'u comes in for Mifiposeti Paea, who drops to the bench, while Matsuda replaces Kotaro Matsushima, who according to Hammett "hasn't got over the hamstring injury" that he picked up 15 minutes into the first test.
"Rikiya is a confident young man and very strong. For a young guy he has a very good rugby brain," Hammett said of the Teikyo University student.
And of the returning Sa'u, the former All Black said, "Male gives us another string to our bow in terms of he is quite a threat with ball in hand."
Elsewhere there is just one other change in the match-day 23-man squad with powerful No. 8 Ryu Koliniasi Holani named among the replacements at the expense of Hiroki Yamamoto.
In the forwards lock Hitoshi Ono gets ever closer to a century of test matches as he's set to play his 98th game for Japan, while tighthead prop Kensuke Hatakeyama will be winning his 75th cap.
"Scotland have made a few changes but you are talking about a squad that has played a lot of Six Nations together and I don't believe that will weaken them in any way," said Hammett. "In fact it can make them stronger as some players will have the chance to prove themselves."
Saturday's game will be played in front of Emperor Akihito and Empress Michiko, just the second time the imperial couple have watched a rugby game — the first being an All Japan Championship game between Kobe Kobelco Steelers and Yamaha Jubilo on Feb. 23, 2014.