>>48547510No, there's no "Fire" or "Leaf" characters. Since they're just remakes, they brought back the Kanto trio for a new adventure in the Sevii Islands. This is generally the case in the other manga arcs too. If the game is a third version expansion, they add a character. If it's a sequel with new trainers, they add new characters. If it's a remake, they just reintroduce those protagonists and have them deal with the new content.
The concept of Fire Red and Leaf Green is brought up though, during a scene relating to those two eternal rivals training their Charizard and Venusaur together to unlock Blast Burn and Frenzy Plant.