- "Miis can also have different personalities. Some will get along better than others..."
- — Tutorial, Tomodachi Life
A Personality is a mechanic featured in the Tomodachi series that are used to determine how a Mii behaves in the game. The personality of a Mii is determined by a quiz when the character is created. There are sliders for the following criteria: Movement, Speech, Expressiveness, Attitude, and if the Mii is overall quirky or normal.
In the official Website for Tomodachi Life, there is a personality quiz that people can take, regardless of if they have the game or not.
Personalities are first featured in Tomodachi Collection, featuring four categories: Calm, Cool, Fun, and Dry, with 4 sub-categories for each. Each personality play a role in interaction with other Miis. The different personalities of each Mii will determine how they act, who they get along or do not get along with, who they will have a successful relationship with, and their likes and dislikes on certain items are, such as clothing and Interiors.
A Mii's idle and walking animation depends on what their personality is. For instance, Calm Miis will sway their arms in a straight motion, while Cool Miis will stand in a thinking pose. In addition, a Mii's starting Interior and pose are affected by what personality they are.
Personalities are featured once again in Tomodachi Life, functioning the same way as its predecessor with little to no changes. The only major difference is all of the personalities are renamed in this game, such as Calm being renamed to Easygoing.
However, there are other things added to this game that are also determined by personality, such as the interior design and roof color of the house of a married couple. Additionally, when a Baby is born, the color of their clothes is determined on the personality they are given, as well as the color of the starting clothes they gain after they grow up.
Personalities remain unchanged in Miitomo, with the exception of Buddy and Free-Spirit being renamed as Confident and Individualist, respectively. In this game, A Mii with a specific personality also gain music when the player enters their room, such as a soothing tune for Easygoing Miis. Besides this, no major additions have been made.
In Miitopia, personalities receive a dramatic alteration in mechanics. Rather than inputting information that determines a Mii's personality, the player instead chooses between five pre-established personalities: Kind, Energetic, Laid-back, Cool, Stubborn, Airheaded, and Cautious. In addition, each personality will offer various Quirks in battle or in the overworld, such as a Kind Mii Donating a snack to a Mii that does not have one, or a Stubborn Mii Bracing For Impact when a Monster attacks them.