Lance Higbee is just a typical card shop clerk who teaches kids how to play Duel Monsters. However, by night he also steals cards from the local corrupt police force under the guise of the Red Rocket, and then sells them at the shop with his two best friends. One night, during an otherwise normal run to the shop's "supplier", a portal unexpectedly transports him to the magical land of Equestria. Among all of this, supposedly dead Duelists begin to show up in Equestria and wreck havoc on the unprepared masses, for which Lance is the only answer they have to the threat.

Set during a non-descript time in the middle of Season 8 Pony side and 70 years after the end of 5D's Yugioh side, the in-universe card pool is roughly as big as the current TCG/OCG cardpool, and some plot relevant decks are mass produced in universe