- Pronouns
- she/her
- MarioWiki
- Mario
I think it has to do partially with the cutscene in Mario Tennis. Luigi taunted at Waluigi. Looks like their rivalry was already there, though. Maybe Wario spread nasty lies about Luigi to try to get Waluigi for his cause to make the rival pair miserable and Waluigi is just a proud, arrogant guy who doesn't like similarly named guys especially if they beat him at tennis. Many times.