The following contains spoilers for Episode 9 of Tomodachi Game, "Hurry Up and Switch Sides," now streaming on Crunchyroll.
The previous episode followed the start of the third game, 'Friendly Hide-and-Seek,' where Yuichi left the hider, Mikasa, in a cave and never returned. Unfortunately for Mikasa, the game prohibits the hider from moving from their hiding space. This includes acquiring food. Therefore, it is Yuichi and Maria's job to provide him with something to eat. This rule became dangerous and risky after Yuichi told Mikasa to trust him before disappearing for days. This left Mikasa to starve, who ultimately began hallucinating.
The episode reveals that Yuichi was aware of the other group's plan and refused to let them win, even at the risk of starving Mikasa. Much to everyone's shock, including Manabu, Yuichi asks Group K if he could switch teams.
Group K's Decision
The members of Group K argue about this with one another. Ultimately, they agree to ask their Captain to make the final decision. However, before they can, Yuichi begins chuckling, notifying them that he finds it ridiculous that they can't make a simple decision without their Captain.
As he continues to taunt them, one of the Group K members rushes to punch Yuichi. But before he can strike him, his teammate quickly stops him and reminds him that it's against the rules. This team member hurries to call his Captain, who ultimately refuses to allow Yuichi to join their team because he believes they will win without him, anyway. The Captain also tells one of the Group K members that if Yuichi really wants to join, then the girl must join as well.
Two Days Ago
Maria, who is actually part of the Tomodachi Game management (which Yuichi may already know), narrates that although the Group K Captain is clever, Yuichi is much more intelligent. This is when the viewers are shown a flashback of what occurred two days ago. After Yuichi leaves Mikasa in his hiding place, he heads away with Maria, who asks him about his plan to win. However, Yuichi replies that the plan is to do nothing for the next two days in order to give Group K the impression that he is not a threat. Yuichi continues stating that he'll announce that he wants to switch sides on the third day. If he's able to switch, he plans to make them reveal their hiding spot. But he expects this plan to fail, and the only other sure way to win the game is to follow the other team when they deliver the food.
Maria asks him why he thinks Group K is aware of this strategy. Yuichi explains that in a regular game of hide and seek, they would have picked the smallest member on the team to hide. Instead, they chose the leader, the biggest guy on the team, because he is the most patient and intelligent one from Group K. This insinuates that Group K has thought of the same strategy. Maria inquires about his second plan, should his first plan to switch sides fail. Yuichi asks if she will do whatever it takes to win. Maria remains in character, feigning intimidation, as she agrees to obey him. This is when Yuichi tells Maria about plan B. He explains that he will make small talk and provoke them while looking for something for the first two days, but he doesn't clarify further about the 'thing.'
Plan B
Presently, Yuichi tells Group K that he doesn't want to switch sides anymore. The Group K members grow suspicious of his sudden decision, even inquiring if their Captain was right about Yuichi's plan. Yuichi denies this and instead taunts them by stating that he thinks he'll be able to win easily after observing them. The following day comes, and the Group K members decide to drop off food for their Captain while Yuichi and Maria are asleep. However, while two remaining members from Group K are watching over their opposing team, Yuichi speaks up, insinuating that he's been awake the entire time. One of the Group K members orders the other, Chisato, to watch over Maria while he keeps an eye on Yuichi, who begins engaging him in small talk. However, Chisato quickly interrupts and tells Hyakutaro to trade spots before he reveals too much to Yuichi.
When he makes his way to Maria, Hyakutaro discovers she has disappeared. This throws him into a state of panic as he sprints to possibly search for her or alert Chisato. While Hyakutaro is scrambling in a panic, he finds her, except she is in her undergarments, appearing to have just finished bathing. Hyakutaro's reaction is just as the viewers expect: a flushed and stuttering mess. He stumbles out of the bushes and back towards the camp where Yuichi, Chisato, and Manabu are waiting. Suddenly, Yuichi announces to Maria that he found 'it' and races off, eventually meeting up with her, but not without Chisato and Hyakutaro on their tails. The most jaw-dropping part of this episode occurs right after, when Yuichi pushes Maria off a mountain edge, especially surprising her. Fortunately, Hyakutaro manages to save her while Yuichi makes his escape.
Mikasa's End?
Meanwhile, Yuichi returns to Mikasa with nourishment, and after more than five days, Mikasa finally gets to eat. As they reunite, Yuichi thanks him for trusting him. Additionally, Yuichi reveals what he has meant by the 'thing' he has been searching for. The 'thing,' or, rather, 'person' is the kindest one in Group K. Yuichi concludes that this is Hyakutaro. Eventually, Hyakutaro asks Manabu to switch to Yuichi's group.