The 26-year-old made the move to the Seagulls from Kawasaki Frontale in 2021, and he has represented his current side on 41 occasions, scoring 10 goals and registering eight assists in the process.
The Japan international scored seven goals and registered six assists in 33 Premier League appearances last term, playing an important role in his side claiming sixth position in the table.
Mitoma has another two years left to run on his contract and is not believed to be looking for a move away from the club this summer, which is seemingly in contrast to Moises Caicedo.
Alexis Mac Allister, another key player from last season, has moved to Liverpool, while Caicedo continues to be heavily linked with a big-money move to Chelsea.
According to The Sun, Brighton are now facing a battle to keep hold of Mitoma, with the Premier League champions lining up a move for him.
The report claims that Man City have been focusing on securing a deal for Josko Gvardiol, but the centre-back's arrival from RB Leipzig has now been confirmed, which will lead to the club switching their attention to bringing in a replacement for Riyad Mahrez.
Mitoma, who is said to be in talks over a new five-year deal at Brighton, is thought to be valued in the region of £50m.
Man City head coach Pep Guardiola reserved special praise for the Seagulls attacker when he was questioned on Asian Football ahead of the team's recent friendly against Yokohama F Marinos.
"Well I would say the impact of [Kaoru] Mitoma on the Premier League has been incredible," he told reporters at the time. "He is in the right place with the right manager and his last season was extraordinary.
"And look at what Japan have done in the World Cup in a tough, tough group."
Man City have made two signings this summer, bringing in Mateo Kovacic from Chelsea and Gvardiol from Leipzig, while Mahrez and Ilkay Gundogan have been the notable departures.
Bernardo Silva and Kyle Walker are also being linked with moves away from the club, but Guardiola said on Friday that he wants to keep both players at the Etihad Stadium.
The Citizens will take on Arsenal in the Community Shield on Sunday before beginning their Premier League campaign away to Burnley on August 11.