"Improving the Deck!! (デッキ強化だぜ！！ Dekki Kyōka da ze!!) is the fifth chapter of the Yu-Gi-Oh! D Team ZEXAL manga. It was first published August 3, 2012, in the Saikyō Jump magazine.
After Yuma lost to Shark, his friends are worried about him, and go visit him. However, they are surprised seeing Yuma isn't feeling down at all - actually, that made him want to become stronger. Takashi suggests modifying Yuma's Deck in order to improve it, and everyone decides to help out. Now, with the help of his friends, Yuma rebuilds his Deck, aiming to bring it to 'em and become the Duel Champion!
The following cards appeared in this chapter. Cards in italics debuted here.