From the Super Mario Wiki
“Uh-huh... Oh... Oh! You're going to the volcano because you want to save the princess from some bad guys? What...a touching story! Romantic stories like that... just touch a soft spot in this heart of mine. That does it! I can't let you go alone! I, Sushie, will be by your side until the end!”
Sushie is Mario's seventh party member in Paper Mario. In Super Paper Mario, Sushie appears as a Catch Card found on the eightieth floor of the Flopside Pit of 100 Trials, as well as on a photo in Mario's house.
Her pause menu description states that she "loves romantic stories and cries at the drop of a fin", implying that she is very sensitive and soft-hearted. However, according to the Yoshi children, she is very bossy. She gets her name from the famous Japanese dish.
At Lavalava Island, Mario enters Yoshi's Village and finds that five Yoshi children are missing. Their babysitter, a Cheep Cheep named Sushie, asks Mario to help her find them. When they find the 5 Yoshis, Mario tells Sushie about his quest. Sushie says it's a very romantic story and joins the party. During the fight with Lava Piranha, Sushie's water attacks are quite helpful.
After Mario reaches a dock, he can ride on her back on the surface of water and dive underneath if he chooses.
Sushie has a daughter named Sashimie. During the game, Sashimie sends her mother a letter, stating that she is going to have a baby, meaning Sushie will soon be a grandmother.
Sushie makes an appearance in Super Mario-Kun specifically, the issues with a Paper Mario arc. She follows the role she has in the game the issue is based on.
Names in other languages