Gundam Build Fighters (2013)

Sei Iori comes from a family that runs a small-town hobby shop, and he dreams of becoming a Gunpla Battle champion just like his father. While he’s incredibly skilled at building Gunpla, his performance in actual battles falls short. Everything changes when he meets a mysterious boy named Reiji, who helps boost his confidence and sharpens his combat instincts. With Reiji by his side, Sei enters the 7th Gunpla Battle World Tournament, determined to fight his way to the top.