Introducing the Frontier Brains! (Japanese: フロンティアブレーン出現!Enter the Frontier Brains!) is the fourth chapter of the Pokémon Battle Frontier manga.
The chapter begins with Rald and Sceptile at the Pokémon Center, after having just lost a battle... The scene then shifts to the next day, where Enta is training with his Vulpix and Feebas, while being watched by a photographer from the bushes. The photographer reveals herself however when she approaches Vulpix for a close up shot because it's so cute. After an exchange with the photographer, Enta is told that Rald lost in a battle against someone. He refuses to believe this and searches out Rald himself to find out the truth. Rald admits that he was defeated by a "Frontier Brain", when Enta ask what a Frontier Brain is, Rald tells him that it'd be better if he found out for himself. Enta then returns to find the photographer and asks her about what a Frontier Brain is, and she explains to him that they are the super elite Trainers who reside at the top of each Battle Facility. Enta then decides to start taking them on, starting at the Battle Dome. After battling his way through enough matches, Enta wonders whether this Frontier Brain is the one who beat his Master, but is absolutely dumbstruck when the flamboyant Superstar Dome Ace Tucker appears. Enta sends out Feebas and Vulpix against Tucker's Salamence and Swampert. In the course of battle, Vulpix is cornered, and its last ditch Flamethrower is dodged, with it blowing a hole in the roof, letting rain fall inside. Tucker's Pokémon then defeat Vulpix as he claims victory. Enta however says it's not over yet as Feebas is still on the field. Feebas has its speed increased by its Swift Swim and manages to take down both of Tucker's Pokémon with Blizzard. However, Tucker absolutely refuses to accept that something as ugly as Feebas couldn't possibly beat a Dome Superstar. However, his mind is changed when Feebas evolves into Milotic, the photographer arrives to congratulate Enta on his victory as Rald watches from a distance, impressed by Enta. However he notices something about the photographer, and flashes a grin to himself as he leaves. Meanwhile, Enta announces that now he only has 6 Frontier Brains left and that he's gonna aim to be the greatest Trainer around.