Malo is the little kid that makes fun of everyone he encounters. Below area few ways to make see his rudeness:
Listen to his comments when you’re showing everyone how to use the sword and slingshot.
Enter his shop in Kakariko village and he will say rude things to you.
When you are showing off your archery skills to the children, cancel. He will ask if you need more arrows. Say no and he will ask if you want to give up. Select "I am no quitter". He will then tell you how slow you are.
After the store is closed in Kakariko Village, come back at night. Before morning, he will leave rude comments on his door.