- "We're so excited for our wedding!"
- — Mii, Tomodachi Life
- "We've decided to get married."
- — Mii, Tomodachi Collection
Marriage is a feature in Tomodachi Collection and Tomodachi Life, in which two dating Miis of the opposite gender join together and become husband and wife.
The feature's benefits vary between Collection and Life. In Collection, two Miis that marry will not receive any form of reward other than the game acknowledging them as husband and wife. Life on the other hand provides many more bonuses to a married couple, rewarding them a house in Mii Homes, which they will live in along with their apartments. A married couple can have a baby with the player's permission. Child Miis can also marry through use of Age-o-matic, which will instantly make them 18 years old.
In Collection, the following must be done for two Miis to marry:
- A male and female Mii must be dating.
- Once a certain amount of time has passed and both Miis maintain a good relationship with each other, one of the two dating Miis will reveal that he/she wants to get married to his/her sweetheart, and the marriage will occur automatically offscreen while one of the Miis gives a photo album of the two after successfully marrying. After the slideshow, the two Miis go on their Honeymoon.
In Life, the process of marrying two Miis is slightly more complex:
- A male and female Mii must be dating. Unlike Collection, an adult and a child cannot get married, unless an Age-o-matic is used on the child.
- Once a certain amount of time has passed and both Miis have a really good relationship status, one of the Miis will ask the player that they want to propose to their sweetheart, which will kick off the Marriage Proposal event. During such, the player has to help the Mii propose by alerting them if the sweetheart is thinking about them. If the proposal ends in success, the Mii proposes and the sweetheart will happily agree to marry, which will lead into their wedding, and then their Honeymoon. If the two Miis are children (or if one of them is a child in the Japanese version), they will request for the player to use the Age-o-matic before heading off to their wedding (After the proposal, if successful and both Miis are children, the gift they present you will always be an Age-o-matic). If the player refuses, the wedding will be postponed and the process will have to be repeated.
After the engaged Mii couple gives the player a present, the wedding scene is shown. A bell is shown ringing as white birds fly past, and the camera shows the newlyweds; the groom wearing a tuxedo, the bride wearing a wedding dress and holding a bouquet of flowers, as a cake stands between them. They walk up to each other then face forward happily as we hear applause; their guests are then shown, either their friends, parents or siblings. The men wear suits; the women wear either frilly dresses, loose-fitted dresses, bubble dresses or evening gowns. Then, in an overhead view, the bride tosses her bouquet over her shoulder as the view becomes a gold-tinted photograph.
- When the proposal between two Miis is successful and they are kids, they get changed into their clothes for the wedding after they are turned into adults. However if the proposal is between two adult Miis, they do not get changed.
- Due to the presence of a wedding cake between the married couple, it's obvious the setting is at the reception and not the ceremony.
- It is possible to remarry a different Mii as well as an Ex-Sweetheart/Spouse.
- If a Kid-o-matic was used on a Mii and they get married, then either that Mii won't return to its original height, only growing at the same rate as the opposite Mii, or they won't grow at all.
- If a child has an Age-o-matic used on them, they get married, then get divorced, they will revert back to a child with the text 'The Age-O-Matic wore off.'