Flankers Ernst van Rhyn and Zain Davids and lock Cobus Wiese have all been included in the run-on team, while prop Carlü Sadie and lock Ruben de Villiers will play off the wood.
The team also features an exciting halfback partnership, with the Bulls’ Manie Libbok teaming up with Kings scrumhalf James Hall.
Commenting on the opener, Theron says: “We selected a strong team to lay the foundation for our campaign against a highly motivated Japan side.
“These players all proved their worth in the warm-up matches as individuals and as combinations, and we are excited by what they can do if they play to their potential.
“The players have settled in well since we arrived in Manchester and I have been pleased with the quality of our training sessions and the players’ attitude, and hopefully they will transfer that onto the field.”
Of their opponents, Theron adds: “We expect Japan to be motivated, competitive and they will try to run at us.
“They will also put a lot of effort into the setpieces, so we are anticipating a tough challenge all around.”