In the Land of Mushrooms, some years after the Mushroom Wars, there was an increasing interest in the go-kart sport. The Mushroomites made improvements to this kiddy event, turning it into an intense, furious, and even dangerous sport. The karts' speeds were doubled. The tracks were hugely improved; they were changed from the simple circles of pavement to twisting, turning, hazardous courses, set in the most ridiculous of locations, from a raging jungle river to a frozen glacier. And, most thrilling of all, magic blocks were fitted for the tracks. By passing through these, one would receive an item that could be used to increase one's ability, or crush the ability of another kart racer.

Yes, the new improved Mushroom Kart Racing was a very dangerous sport. Although the karts were made of the strongest titanium steel, there were very little safety mechanisms, and no safety equipment (most kart racers raced in their street clothes). It was also very expensive. Just to compete in a 50cc tournament cost at least 5,000 coins. It became a sport only for the super-elite.

In fact, the first few tournaments that were held only saw eight competitors. Princess Peach was a member of the royal family, so she had no problem paying the hefty fee. Toad, her Mushroom Retainer, was made wealthy by his close connection with the royal family. Mario and Luigi, the famous brothers who fended off the Koopa time and time again, were rich in coins they had collected in their travels, and from the reward Peach had given them. Yoshi, the loveable, energetic dinosaur, was an entrepreneur in the Yoshi apple business, which was all the rage in Toad Town, so he was also able to compete. Wario had spent most of his life coming up with schemes to get rich; not all were successful, but he had made enough to pay for the race. Donkey Kong, hailing from the tropical island with his namesake, had defeated the Kremlings many times, and each time, he had looted their treasure ships, so he had plenty of cash. Bowser was the king of the Koopa, and although it took a bit more to bribe the authorities to allow him to compete with his notorious reputation, he made it in.

In reality, kart racing was a spectator sport.

But that was all before the invention of the Double Dasher. It was a huge improvement over the original kart. It was faster, more maneuverable, more durable, and most importantly, could hold two racers, who used cooperation to succeed. One would be in the driver's seat, while the other would hang onto the back, using items. Many times, the two would switch in mid-race, allowing one a break from driving, or allowing the other to use his special item.

The Double Dasher was much more dangerous as well. The racer on the back had no way of being held on, except by holding the bar with his hands. When the kart would spin out, all that would hold him from the power of inertia was his own strength. Also, although it was illegal, those riding shotgun would often quarrel with other racers as they came along side them.

Because of its danger, the participants demanded a price drop. After all, why pay thousands of coins for something that might cost you tenfold in medical bills?

The price was cut by half, by half, then by four, then by half again. It was finally a reasonable price for people to pay. The elite were no longer the only ones racing. Birdo joined the race, riding with Yoshi. Wario reunited with his brother, Waluigi, at the kart. Bowser decided to spend quality time with his long-lost son by kart racing together, oddly enough.

And a couple of young koopa brothers, neither of who had anything to lose, decided to give the harsh world of kart racing a shot by racing together in the Double Dash Tournament...