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 Mario Kart Wii, Mario Kart 7, 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 update for Dr. Mario World on mobile that added them in their Fire costumes to the game. However, due to the minimalistic nature of the Mario series and Rosalina being largely absent from Super Mario Galaxy 2 in particular, and her having yet to appear an RPG, Luigi and Rosalina don't really have that many more chances to truly interact.

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 such as kart-racing, partying, tennis, golf, and soccer. They are also two of the taller, more introverted, and kindest major characters in the franchise. Both are commonly depicted as lonely with Luigi in Mario's shadow and Rosalina missing her late mother, but both of them know they will always have each other to confide in.

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 have spent time together at the Comet Observatory in between missions, or at the very least, he admires her from a distance. 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. Though Luigi might question whether he is worthy of someone like Rosalina since he so often gets into trouble and needs Mario's help. He even admits his exhaustion after his third adventure, and elects to stay behind at the Comet Observatory, leaving the rest of the Power Stars to his big brother.

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