- "I had a fight with [Mii]. I'm so upset!"
- — Mii, Tomodachi Life (US)
Fights are a feature in Tomodachi Collection, and Tomodachi Life. Two Miis can be angry at each other and depending on how it goes, it may or may not break a friendship or a relationship.
A fight can be spotted when a pair of Miis have the orange friendship icon on their apartment windows. The system that determines fights is entirely random-based. Nothing the player does beforehand nor the Mii's Relationship levels will determine when the two Miis will fight, and if they do, whenever the fight is either a normal, standard fight or a huge, hostile fight. Two Miis that have married have a higher chance of fighting against each other than with other Miis (unless they're looking after a baby).
If the fight fails to be resolved, both Miis can be removed from their respective relationship charts, setting their relationships back to anonymous. If this occurs to two married Miis, this could lead to an immediate breakup request, unless either wants to make up.
Each time the player starts up the game after several hours of not playing, up to three fights will break out at random, depending on the island population. Fights cannot be prevented nor can the causes of the fight be tracked down under any circumstances. Outside of this, if the player sees two Miis arguing in Mii Apartments, they are more likely to start a fight if both Miis show angry reactions. It is at the point that either shifting to another apartment or entering the arguing Mii's apartment will instantly kick off the fight.
- "[Mii] and I got in a fight. I'm so mad now."
- — Mii, Tomodachi Collection
Fights first make their appearance in Tomodachi Collection. A regular fight can be spotted when a Mii has small puffs of smoke coming out of their head. Upon visiting them, the Mii will be angry and upset, and the player has to calm the Mii down. The easiest way to do this is to use certain gifts, such as the bath set, the swing, or the music box, though giving them food, clothing or hats that generates at least a "(s)he really likes/liked it!" works just as well.
Once the Mii is calm, the Mii will go to the apartment of the friend they are fighting with to attempt to make up, waving and apologizing to the other Mii. If the friend accepts the apology, they will also wave and apologize. If the friend rejects the apology, they will say they won't forgive them, causing the other Mii to become Depressed. If the player clicks the Mii's thought bubble twice, they will see a flashback of the fight, depicting the two Miis throwing random treasures at each other while yelling insults.
- "I had a fight with [Mii]. I'm so mad!"
- — Mii, Tomodachi Life (EU)
Fights return in Tomodachi Life, functioning exactly the same as in Collection. In addition to the throwing fights, however, fights can also occur in the form of tugging a teddy bear or an item. Only in Tomodachi Life, after a fight where things didn't end well, the Mii's friend will sometimes have a problem afterwards, depending on its relationship level. They will say that they are sick of fighting and want to make up with the Mii. If accepted, this will play a cutscene where the Mii visits their still sad friend. They apologize back, and the other Mii is no longer depressed, turning its head happily and saying, "Sure.", followed by him/her jumping up and the two dancing together. Once they apologize back, the fight will become solved and the Miis will return to being friends.
There is a way to determine if the Mii's friend will apologize after a fight that didn't end well. If the friend's name is still on the Mii's relationship chart under "Friend (Fight)" after the Mii fails to apologize, it foreshadows that the friend will return to apologize back. This might not happen however, and if the Mii does not wish to apologize back, they stop being friends immediately.
Hostile Fights (or Huge Fight) are also introduced in this game, being when a Mii is so enraged with another, they will appear to have a fiery aura and heavy metal music will play in their apartment. Unlike a regular fight, the Mii is so mad that they refuse to apologize, and any attempt to calm them down will always fail.
The only way to stop a hostile fight is if a random friend of both of the Miis is willing to help them make up. If one does, the request usually generates instantaneously with the actual problem. If they do want to help and the player accepts, a cutscene will begin. In this cutscene, the Mii tries to intervene with the fight between his/her two friends. If they succeed, the two Miis will make up by smiling and waving at each other, then dance while the friend Mii applauds happily as a happy tune plays. If they fail, the two Miis will continue to fight and instantly end their friendship and the friend Mii frowns and ducks for cover, while shaking his/her head in sadness.
Oddly, Miis that have been in a standard fight long enough cannot enter a hostile fight if the fight goes on long enough, and vice versa.
Fights, reffered to as Quarrels, are confirmed to appear in Miitopia, functioning as one of many interactions that occur between two Miis. In this game, if a Mii with strong bonds to another Mii suddenly talks to another Mii, the Mii they have bonds with will quickly become jealous and cause trouble to them. This eventually builds up to a dispute between the two Miis, causing their relationship level to drop.
- Oddly, when a third Mii attempts to resolve a hostile fight, the two Miis that would normally be represented with the flaming aura are instead shown with puffs of smoke, as if the Miis had a normal fight. This is possibly to make the Miis more noticeable, as the fiery auras obstruct their sides and back.
- You can tell if the apology is going to be accepted or rejected by the two Miis' relationship; if one of them has a low enough status ("Getting Along OK" or lower), there's a chance they'll be rejected, even if the other Mii has a high level. In the case of a hostile fight, if either Mii has said low status, there's a chance the fight will fail to be resolved.
- If the Mii is the child of a couple, or has a sibling, they will not fight. Mii couples will also not fight if they were originally best friends before they started dating.
- Usually there's a pause after the Mii apologizes to its friend; at other times, the other Mii will immediately answer.
- It's possible for a fight to occur when a Mii is asleep.
- A married couple will not get in fights against each other if they have a baby, making babies the only method of preventing spouses from fighting.
- If you witness a fight from outside an apartment and you choose to enter, the Miis won't stop what they're doing, turn at, and walk to the player when the doorbell rings, and it will take a longer time before you enter the apartment.
- A fight can resolve itself, but the two Miis will stop being friends.