Luisalina

Luisalina is the het ship between Luigi and Rosalina from the Super Mario fandom.

Canon
In Super Mario Galaxy, Mario meets Rosalina, Guardian of the Lumas, while looking for Princess Peach. Along the way, he rescues his younger brother Luigi from ghosts. Luigi tries to help Mario collect Power Stars, but each time he needs Mario to come save him. When Mario frees Luigi in Battlerock Galaxy, Luigi tells him that he has to tell Rosalina that he found the Power Star he collected before giving it to her. They also have their picture taken together if Luigi completes the game, alongside the Toad Brigade.

They later both appear as playable characters in Super Mario 3D World, various spinoffs, and even Super Smash Brothers for 3DS/Wii U (Including in Rosalina's reveal trailer) and Ultimate. Most recently, the two were paired in a March 2020 Dr. Mario World update, which added them in their Fire costumes to the game.

While they may seem to be two worlds apart, they quickly discover that they may have more in common than they thought, as they enjoy many similar hobbies. Both are commonly depicted as lonely, but both of them know they will always have each other.

Quotes
"Yeah, yeah, you want this Power Star, right? Only if you tell Rosalina I found this one!"

--Luigi, Super Mario Galaxy

Fanon
Luigi makes it pretty obvious that he at the very least wants to impress Rosalina when Mario rescues him at Battlerock Galaxy, so they do spend some time together at the Comet Observatory in between missions. At the end of the game, Luigi and Rosalina even get their picture together, similar to how Peach posed with Mario when the player beats it with him.

Since both Luigi and Rosalina share introverted traits, a lot of fan art has one or both of them blushing. They are often depicted hanging out, comforting one another, running through worlds, or sometimes just showing affection for each other.

Fandom
FAN FICTION
 * Luigi/Rosalina (Super Mario) tag on FanFiction.Net
 * Luigi/Rosalina (Super Smash Bros.) tag FanFiction.net
 * Luigi/Rosalina (Super Mario) tag on FanFiction.Net
 * Luigi/Rosalina (Super Smash Bros.) tag FanFiction.net