Ever since he was little, Mallow had cried easily. The other tadpoles he grew up with teased him, calling him crybaby, but at the same time they accepted it was just how he was. And over time Mallow grew to accept it as well, even making jokes about himself and his little quirk.
The day he discovered the truth about himself and his parentage, he promised himself he wouldn't cry anymore. Mario was a real hero, and he needed a strong sidekick to help him out. I'm strong, I'm brave, and I'll fight my way through any danger!
Then came the day they saved Nimbus Land from Valentina and Dodo, and Mallow met his real parents for the first time.
"M-Mom...Dad..." He sucked in his lower lip, fighting back oncoming tears. Princess Toadstool gently tapped him on the shoulder.
"It's okay," she said, and as he gave into the tears and embraced his mother and father, he realized they were crying too.