Chocolate Disco (チョコレート・ディスコ Chokorēto Disuko) is the sixteenth story arc in Steel Ball Run.
At 3:59 PM near a park south of the Independence Hall, Johnny and Gyro spot Diego and Wekapipo following him. Johnny notices an unidentified horseshoe trail but doesn't suspect anything. While Gyro tries to approach Diego's position and Johnny watches from afar, Johnny sees that Gyro, at the corner of a building, is being surrounded by both President Funny Valentine and his henchman D-I-S-C-O. Johnny tries to warn Gyro but mysteriously, Gyro doesn't hear him. Suddenly Johnny is shot by an unknown party, and barely escapes in the sewers with Tusk ACT3.
Gyro notices Johnny's absence, and sees that one enemy has retreated. Warning D-I-S-C-O not to do anything, Gyro rushes toward his horse and Johnny. A grid appears on the ground and a startled Gyro throws a Steel Ball toward D-I-S-C-O, which mysteriously teleports above Gyro and hits him instead. Disco then opens a bottle of acid and pours it on the ground.
- 17 (97) D4C