Tomodachi Game

The Tomodachi Game (トモダチゲーム) is the central theme of the series. It is a game organized as a business, mainly for debtors to pay their own debts. The main overseer of the games played is a mascot named Manabu. Each game has its own unique rules to follow.

"Gods"
This is the term given to the audiences who have provided funding for the game. Manabu considers the audiences their creators, making them their "Gods". They are mainly shown as special live viewers in Group C's second game, "Backbiting Sugoroku". Their live chats can be seen floating in the sky.

Debt & Participation Fee
The participation fee is presumably 10% of the players' total incurred debt. The total incurred debt is then divided amongst the number of players. The debt can be decreased by playing games. It won't increase after the game is over. However, the players will each shoulder the remaining debts they have.

Players can choose to disjoin the game. The players will be immediately set free. However, the participation fee will not be returned to them. Thus, the person who owes the debt in the first place will have to shoulder it on their own.

Name Plates
The players can track of their current debt amount on name plates. It will be labeled as minus (-) (current debt amount). Those resemble the ones given out in schools. If a player clears a game and their display reads zero, their debt is also cleared.

Players must first choose the name plate with their name on it. They must then pin it on their right chests. There is a digital display behind it and players must check themselves, if the numbers are being displayed properly.

There is an important rule to not show the numbers on the plates to others. The rule applies even outside the tomodachi games. If someone breaks the rules, their debt will become double the amount (x2). However, players are allowed to say their numbers out loud.

Regular

 * "Kokkuri-San" Game (Group C First Game)
 * Backbiting Sugoroku (Group C Second Game)
 * Friendship Hide-And-Seek (Group C & Group K Joint Game)
 * Friendship Janken (Special Omake Chapter)
 * Friend-Sin Trial (Group C Fourth Game)

Adult

 * Friend's Prison Game
 * All Bet
 * Friends Murder Game
 * The Friendless Game