The Lost Game System

"The Lost Game System" is the fifth chapter of the Story Mode in Mario & Sonic at the Olympic Games Tokyo 2020.

Plot

Upon investigating the Tokyo '64, Tails discovers that Mario and Sonic are competing with Bowser and Dr. Eggman inside the game, confusing Luigi and company as to why they would compete in such a situation. However, Bowser Jr. suddenly appears, declaring that only he is allowed to have fun, and takes the system from Luigi. Even after the group explains the situation, Bowser Jr. is still skeptical and leaves with the Tokyo '64 to find out for himself. After Amy suggests that they check other venues, Tails counters with the fact that they need passes to access them, and he goes with Luigi to find some. They go to Tokyo Tower, where they find Silver, who was sightseeing, and ask him about passes. He explains that he had passes for the Tokyo Aquatics Centre and the Aomi Urban Sports Park, but he dropped them while he was climbing up the tower. Tails climbs the tower and obtains the passes, which Silver lets him keep. He also joins the party due to how serious their situation seems. With their pass, they go to the Aomi Urban Sports Park, where they confront Bowser Jr., who is being accompanied by Rouge. He still refuses to return the Tokyo '64, and Rouge, who sides with him, challenges Daisy to Sport Climbing, saying they will return the system if she loses, to Bowser Jr.'s dismay. After Daisy beats Rouge, they return to the ground and realize Bowser Jr. already left, deducing that he ran off to another venue. They track him to the Tokyo Aquatics Centre, where he is now being protected by Wendy. Silver decides to challenge Wendy to 100m Freestyle and wins. Wendy fakes being a sore loser to distract the heroes while Bowser Jr. escapes to find Eggman Nega. Luigi and Tails go to Nippon Budokan, only to find Bowser Jr. already there with Eggman Nega, who is intrigued by the device. Luigi decides to challenge Eggman Nega to Karate in order to get the system back and wins. Accepting defeat, Eggman Nega is ready to give the Tokyo '64 back to the heroes, only for Bowser Jr. to intervene and tell him that he has to investigate it. Upon further investigation, Eggman Nega realizes the system is one of Dr. Eggman's creations. After Tails explains that Mario, Sonic, Bowser, and Dr. Eggman got trapped inside it, Eggman Nega decides not to give it back, and he leaves with Bowser Jr. to analyze the game further in order to free Bowser and Dr. Eggman. Luigi and Tails resolve to find them before they free the villains and leave the heroes inside forever. As Luigi and Tails do not know where to find Bowser Jr. and Eggman Nega, a nearby Omochao suggests that they get help from Vector, who is competing in the Discus Throw at the Olympic Stadium, and the two go there in order to do so.

Locations	Challenges	Events	Minigames	Party members gained	Guests unlocked
Ariake Urban Sports Park	N/A			Tails	N/A
Tokyo Tower	N/A		Tower Climb	Silver
Aomi Urban Sports Park	Daisy vs. Rouge	Sport Climbing	N/A		Rouge
Tokyo Aquatics Centre	Silver vs. Wendy	Swimming	N/A		Wendy
Nippon Budokan	Luigi vs. Eggman Nega	Karate	N/A		Eggman Nega