Kafanju

Kafanju is a Het ship between Kafei and Anju in The Legend of Zelda series. It specifically applies to Majora's Mask as that is the game that those characters appear in.

Canon
It is unknown exactly when Kafei and Anju fell in love but their relationship stems from their childhood. They eventually got engaged by the time that Link arrived in Termina. The two were planning to get married during the Carnival of Time. Anju made a moon mask for Kafei while Kafei made a sun mask for Anju as that was a part of the tradition. Unfortunately, the Skull Kid turned Kafei into a child and then a thief named Sakon stole his sun mask. He felt that he could not face Anju without his mask for her so he went into hiding for over a month.

The whole town went searching for Kafei after he disappeared. Many began to believe that he wanted to break off his engagement with Anju. Anju's mother tries to convince to give up on him and believes that he ran off with her best friend Cremia as she also had a crush on Kafei. However, Anju later receives a letter from Kafei but still does not learn where he is. If Link obtains Kafei's mask and talks to Anju at the right time, he can get involved.

Anju sends a letter back to Kafei if Link agrees to help which allows him to meet Kafei. He explains everything to Link and asks him to give his pendant to Anju. If Link does so, Anju will regain hope and stay in Clock Town. If he doesn't, she will cave into her mother's demands and flee to Romani Ranch. If Link manages to help Kafei get the mask back, he and Anju will reunite late at night before the carnival.

If Link does everything right, Anju and Kafei will reunite and embrace. Anju will not seem to care that Kafei is in the body of a child and Tatl will remark that they look more like a mother and a child than a couple. After exchanging masks, they will create a Couple's Mask and present it to Link. They will then ask him to flee while they "great the morning together" even though the moon is about to fall. If Link obtains the Couple's Mask before saving Termina, Anju and Kafei will get married on the day of the carnival.

Fanon
Kafanju is a rather popular Zelda ship and is possibly one of the most popular ships that does not involve Link. Majora's Mask has a huge side-quest that involves reuniting the two and it known as the largest side-quest of the game. It is also difficult to complete while doing everything right but many find it to be rewarding in the end. They fact that Anju and Kafei are ready to die together while the moon crashes into Termina is considered to be a tear-jerker by many.

Trivia

 * While their wedding is shown at the ending of the game, it shown from Kafei's point of view. As such, a model of his adult form is never shown. If one hacks the wedding scene into the game, all characters shown will be present but Kafei will not be visible. However, in the manga, Kafei's adult appearance is shown in a flashback.