A sweetheart (known as special someone in the European version of Tomodachi Life and lover in Tomodachi Collection and Tomodachi Collection: New Life) is a term for Miis who become a boyfriend/girlfriend after a successful confession or set up. Various problems can cause sweethearts to breakup.
Miis can become sweethearts in two ways: The first way is the love confession, where one Mii develops feelings for their friend, so they confess their love to them and if they accept, they start to date; if not, the Mii will gain sadness.
The second way is a set up, where a friend of two random friends of theirs will set them up on a date, and if it ends with them wanting to hang out again soon, they will automatically start dating without confessing their love. If they "Are just going to be friends for now.", the Mii trying to set up will gain some happiness, and the two Miis become friends. Sometimes if the setup fails with them "not hitting it off so great", one of the Miis will question why their friend would want to set them up with the other Mii. This is exclusive to Tomodachi Life.
Miis may want to break up if they argue a lot or their relationship status is low. It is also possible for a dating Mii to leave their sweetheart for another Mii. After a breakup, both people in the relationship may become depressed. If the relationship status remains very good for long enough, one of them will eventually want to propose and get married.
- Sometimes sweethearts or a married couple can visit each other at either of their Mii Apartments and stare at each other lovingly, as hearts appear. If the player watches them like this long enough, both will notice the player and jump up, surprised, then have a freak out for a moment before turning around and facing away from each other with surprised expressions. After a few seconds they then find something else to do. Sometimes they go back to being romantic, or do another activity. If the player sees the sweethearts being romantic while sitting down/talking, they will not freak out.
- Sometimes when the player watches the sweethearts stare at each other lovingly, the Miis will not freak out no matter how long the player watches. If this is the case, then the sweethearts will eventually sit down and one of the Miis will be talking occasionally.
- Oddly, even though sweethearts are in the game, they don't ever kiss or hug each other, possibly because of the target audience (hugging and kissing would seem uncomfortable to younger players).
- In the English localization of the game, a child Mii cannot fall in love with an adult Mii and vice versa. However, something like this can happen if two child Miis are dating and one of the Miis turns 18 (20 in the Japanese Version) (which would consider them an adult) before they get married. In that case, only the Mii that is still a child would have to be sprayed by the Age-o-matic before they get married.
- If you have two Miis that are sweethearts, then you are not allowed to change their birthdays so that they would be outside of their original age group. It is possible, however, to change a kid Mii's birthday so that they turn 18 in the near future (such as tomorrow) which then lets you have one sweetheart that is an adult and one that is a kid.