What are some interesting plot ideas for a Mario x Luigi fanfic?

One idea could be that Mario and Luigi find a magical lemon tree in a hidden part of the Mushroom Kingdom. The lemons from this tree have special powers that they have to figure out how to use to save the kingdom from a new villain. For example, the lemons might give them temporary super strength or the ability to fly. Another plot could involve Luigi accidentally getting lost in a lemon - themed dimension while trying to find a rare ingredient for a recipe. Mario then has to brave this strange new world filled with lemon - based creatures to rescue his brother.

One idea could be that Mario and Luigi get transported to a strange new world where the rules of their own world are all mixed up. They have to use their combined skills in a whole new way to find their way back home. For example, Luigi might have to be more brave and take the lead in some situations while Mario has to use his speed in different ways than he's used to.

Princess Peach would be a great addition. She could be in trouble as usual, and Mario and Luigi have to rescue her. But this time, she could also play an important role in helping them solve a mystery or defeat a powerful enemy. For example, she might have some knowledge about an ancient artifact that the brothers need.

Another plot could be that Bowsette accidentally casts a spell that makes Mario forget all about his previous adventures and relationships. Bowsette then has to re - introduce herself to Mario and try to make him fall in love with her from scratch. This would involve her showing him the beauty and magic of the Mushroom Kingdom in a new light, while also facing challenges from other characters who are suspicious of her motives.

A plot could involve a new villain that infects Bowser's body and Mario and Luigi have to go inside to fight the source of the infection. Along the way, they learn about Bowser's past and his insecurities. This could lead to a change in their relationship with Bowser, from just enemies to something more complex like reluctant allies, as they all have a common goal to get rid of the new threat.

One idea could be that Pauline gets kidnapped by Bowser and Mario has to go on an extra challenging adventure to save her. He might face new types of enemies and obstacles along the way.

A possible plot could be set in a parallel universe where Wendy is not a villain. She and Luigi meet at a grand Mushroom Kingdom festival. They both share a love for a particular type of mushroom - based food that is rare at the festival. As they search for this food together, they face various challenges like competing with other characters for the last piece, and through these shared experiences, they fall in love.

There are fanfictions where Mario and Luigi swap their roles. Luigi becomes the more heroic and fearless one while Mario is a bit more timid. This switch - up can lead to really funny and unique storylines as they face their classic enemies in new ways.

One idea could be that Mario and his friends are transported to the RWBY world and they have to team up with the RWBY characters to fight a common enemy like a powerful Grimm that has some sort of connection to the Mushroom Kingdom's villains. Maybe Bowser has made a deal with this Grimm to take over both worlds.

One plot idea could be a race across different dimensions. Sonic, with his speed, Mario, with his jumping skills, and Yoshi, with his unique abilities, could be competing to find a powerful artifact lost in these dimensions. Another could be a team - up to stop an evil force that threatens both their worlds. The evil force might be trying to steal the chaos emeralds from Sonic's world and the power - ups from Mario's world. And a third idea is a friendship - building adventure where they have to help Yoshi find his long - lost family in a strange new land that combines elements of both Sonic and Mario's universes.