Cardiff Blues flanker Josh Navidi has been selected to make his international debut at the Prince Chichibu Memorial Stadium, with Tom Prydie (Dragons), Rhys Gill (Saracens) and Andries Pretorius (Blues) also drafted into the starting XV.
Tour head coach Robin McBryde saw his side win the first test 22-18 in Osaka last weekend and will be looking for a sixth consecutive victory on Saturday. The only change in the front row sees Saracens prop Gill come into the side alongside Emyr Phillips (Scarlets), who will win his second cap, and Blues prop Scott Andrews.
A new-look back row sees Ospryes' James King switch to blindside, Navidi comes in at openside flanker and Pretorius starts for the first time for Wales at No 8. There is just one change behind the backline where Prydie comes in on the wing.
"We were proud of the side's effort last weekend but know we will have to step it up again on Saturday," said McBryde. "It was good to see the character of the squad come through in the first test and we will need that again.
"The players have again all put their hands up for selection making it a tough call for us and that shows their determination to get out on the field and represent their country.
"Japan showed what they are capable of last weekend and we know we will have to be at our best to get the second victory and finish the season on a high."
Wales team to play Japan in Tokyo on Sunday: Liam Williams; H Robinson, O Williams, J Spratt, T Prydie; D Biggar, Lloyd Williams; R Gill, E Phillips, S Andrews, B Davies (capt), L Reed, J King, J Navidi, A Pretorius.
Replacements: S Baldwin, R Jones, C Mitchell, A Coombs, D Baker, T Knoyle, R Patchell, D Howells.