The fixture, the first-ever between the Lions and Japan, has been organised to help Gatland’s team prepare for the upcoming tour of South Africa which will culminate in a three-test series against World Cup champions, the Springboks.
Auckland-born Aki, who attended Manurewa High School, moved to Ireland in 2014 to play for Connacht, and made his debut for his adopted country in 2017 under New Zealand coach Joe Schmidt.
Aki will make his debut for the Lions against the Brave Blossoms, who are coached by Kiwis Jamie Joseph and Tony Brown, at Murrayfield.
"We’re anticipating a tough game against Japan – a side that like to play at a high-tempo and shift the ball," Gatland said in a statement.
"We saw throughout the World Cup they have attacking threats across the park and a solid defence and set piece.’’
All Blacks supporters will take a keen interest in the Springboks’ performances against the Lions, given they are set to meet them in the Rugby Championship.
The All Blacks have not met the Springboks since they played each other in the first World Cup pool game in Japan in 2019 after the world champions played no rugby in 2020.
The Lions have been based on the island of Jersey ahead of the game against Japan.
British and Irish Lions team to play Japan:
Liam Williams, Josh Adams, Robbie Henshaw, Bundee Aki, Duhan van der Merwe, Dan Biggar, Conor Murray, Jack Conan, Hamish Watson, Tadhg Beirne, lun Wyn Jones, Iain Henderson, Zander Fagerson, Ken Owens, Rory Sutherland. Reserves: Jamie George, Wyn Jones, Tadhg Furlong, Courtney Lawes, Taulupe Faletau, Ali Price, Owen Farrell, Anthony Watson.