Soriel

Soriel is the het ship between Toriel and Sans from the Undertale fandom.

Canon
At one point, Sans describes how he used to speak with a woman who was on the other side of a wall and they enjoyed puns together but one day she just disappeared. One day, the woman made Sans promise to protect any humans who exits through the doors, a promise Sans keeps unless the player chooses to do the Genocide Route.

In the Pacifist Route, Sans and Toriel see each other for the first time. They recognize each other to be the ones they talked to before as they recognize each other's voices. It is only at this moment that they learn each other's names. After the Barrier is broken, Sans sometimes uses Toriel's phone to text for her.

In the Exiled Queen ending, if Papyrus was killed, Sans and Toriel become roommates. Sans cannot bear to tell Toriel what Frisk did. If Papyrus is alive, the two brothers frequently visit the Ruins and play board games together. They also sometimes convince Toriel to leave the Ruins, as long as one of the brothers stays there to look for fallen humans.

Fanon
People like to pair Toriel and Sans due to the fact that both of them like puns. In Soriel fanworks, the two characters typically enjoy puns together and often annoy others by doing so.

Another reason is that the way the two characters look at each other during the True Pacifist Route interactions befirey Flowey abducts most of the monster SOULs can be interpreted as romantic.

Its biggest rival ship is Asgoriel, the ship between Asgore and Toriel. Soriel shippers usually point out that Toriel refuses to get together with Asgore at the end of Undertale. Soriel fanworks commonly include Toriel rejecting Asgore in favor of Sans, leaving Asgore sad. Other Soriel shippers think Asgore deserves better and pair him with someone who isn't Toriel.

The ship also has haters. Besides it getting in the way of Asgoriel and popular Sans pairings, the two characters also have an unclear age difference. Some see Toriel as being too old for Sans, especially chronologically. The ship can also be viewed as necrophilia due to Sans being a skeleton, although a counter-argument for this is that skeketons are simply a normal monster species. Another reason to not ship them is because Sans is seen as too lazy to commit to a relationship. Some think Sans and Toriel are simply just friends, and shouldn't be anything more than that.

The ship is a common target of shipping wars, as it has both rapid fans and haters who insult the opposing group.

Fandom
AO3

DeviantArt
 * soriel tag on DeviantArt
 * sansxtoriel tag on DeviantArt
 * soriel_undertale tag on DeviantArt
 * Sorihell fanclub on DeviantArt
 * Toriel-and-Sans fanclub on DeviantArt