The former Harlequins prop will make his first appearance at the tournament in France after shaking off a chest injury that kept him out of the 27-10 victory over Argentina.
Joe Marler also starts in the front-row, with Ellis Genge dropping to the bench, and Lewis Ludlam steps up from the off at No 8.
Ben Earl shifts across the back-row to openside flanker, with Billy Vunipola on the bench after his high-tackle red card suspension.
Bristol star Sinckler was one of former head coach Eddie Jones’ most trusted lieutenants, but the 30-year-old has lost his usual Test rhythm since Borthwick took charge earlier this year.
The powerful front-rower enjoyed a fine pre-season training camp with England, only to pick up a niggly chest issue that held him back across the four World Cup warm-up matches last month.
Veteran tighthead prop Dan Cole has been drafted back into England’s ranks after a three-year absence, and the Leicester stalwart locked down the scrum against Argentina in Marseille last Saturday.
Now Sinckler will have his chance to state his World Cup case, as England field a side showing three changes from last weekend’s Argentina win to take on the Brave Blossoms.
Sinckler was only able to feature in two cameo appearances off the bench in England’s four-match warm-up programme last month, so the 30-year-old will be itching to make up for lost time now he is both fit and back in the starting line-up.
Defence coach Kevin Sinfield heaped praise on Sinckler for quickly fighting back to full fitness after that problematic chest injury.
“He’s worked incredibly hard, he’s fit and ready to go now, and that’s after joining team sessions at the back-end of last week,” said Sinfield.
“He’s a good guy, he works incredibly hard, he’s a great character who makes people laugh and he deserves his spot. Competition for places is really good at this moment in time in this squad.”
Sinckler was one of England’s standout stars at the 2019 World Cup, but was knocked out in the first minute of the final against South Africa. England lost out 32-12 to the Springboks in Yokohama in that showpiece clash four years ago.
Sinckler clearly has unfinished World Cup business and will set about taking care of that this weekend.
Vunipola will add power to England’s squad, having completed his high-tackle suspension. The Saracens No 8 will be another England star seeking a big contribution this weekend.
Vunipola missed the final few months of last season with a knee problem that eventually required minor surgery to fix.
The 30-year-old had to battle to force his way into England’s World Cup squad ahead of Harlequins’ Alex Dombrandt, who was a regular starter during the Six Nations.
Head coach Borthwick recalled Vunipola for the World Cup in a bid to boost England’s direct, ball-carrying threat, and now the Sydney-born loose forward has the perfect chance to deliver a top-level showing.
“It was both pleasing and important that we were able to start our campaign with a good win against Argentina last Saturday,” said Borthwick.
“It was incredible to see so many of our supporters in the stadium in Marseile.
“Their support means a great deal to the team. We hope that we were able to provide the supporters both here in France and at home with some great memories, and we are setting out to do the same again this Sunday in Nice.
“We are looking forward to the challenge of playing a Japan side that will be full of confidence following their comprehensive win over Chile.”
England team to face Japan
Starting XV: Steward; May, Marchant, Tuilagi, Daly; Ford, Mitchell; Marler, George, Sinckler; Itoje, Chessum; Lawes (capt), Earl, Ludlam.
Replacements: Dan, Genge, Stuart, Martin, Vunipola, Youngs, Smith, Lawrence.