When the fifth Star Piece of Star Road fell into the sunken ship, Johnny took it. Mario came looking for it, but Johnny was not about to give it up without a fight. He and four Bandana Blues fought Mario, Mallow, Geno, Bowser, and Peach. Mario and his team won, and so Johnny respected him for this and gave him the star piece.
When Mario returned to Seaside Town, he found that its inhabitants were locked up and replaced by Smithy's lieutenant Yaridovich. He forced Mario to give him the Star Piece, having tricked him disguised as the town elder, whom Yaridovich tortured if Mario didn't give it over. Yaridovich attempted to escape on Blade, the Axem Rangers' ship, but they did not show up, so Yaridovich decided to swim away, but Johnny jumped out and stopped him, cornering Yaridovich so that the only way out was to defeat Mario. It was Mario and his party that defeated Yaridovich.
Johnny was last seen looking into the sunset after Smithy was defeated.
He also had a cameo appearance in the credits parade, at nighttime when the figure of his ship was lit up by a star.
Johnny has 820 HP, 85 attack, 80 defense, 25 magic attack, and 60 defense. He can use the attacks Skewer, Mega Drain, Diamond Saw, and Get Tough. He fights alongside four Bandana Blues. If all four are defeated, Mario and Johnny will fight 1 on 1, excluding Mario's partners from the battle. If even one Bandana Blue is still in the battle, he will not do this.
His Psychopath thought says "Whoa! It's all over!"
- Johnny plays a similar role to Cortez from Paper Mario: The Thousand-Year Door. Both are pirates who are initially enemies of Mario, but then get respect for him after being defeated in battle, and help them fight one of the main villain's henchmen. In both instances that star they give to Mario is blue, presumably a reference to the sea.
- Johnny is one of three characters whose battle sprites are different, and bigger, than their sprites outside the battle. The other two are Valentina and Culex.