Emerald (Japanese: 第六章 エメラルド編The Sixth Chapter: Emerald) is the sixth chapter of the Pokémon Adventuresmanga, consisting of four volumes. It began serialization in February 2005, and ended in October 2008.
On the fifth day, the scale gets a bit bigger. Emerald meets Ruby and Sapphire for the Battle Dome challenge and, while they don't realize it at the time, on the same day they come across Red, Green, Blue, Yellow and Silver who are still in the state they ended the last chapter in.
When this chapter was being published in the magazines, it was known as the Battle Frontier chapter (Japanese: バトルフロンティア編Battle Frontier chapter). At the time, this chapter was the only arc of Pokémon Adventures not named after a game.