Candace and Vanessa's relationship

Candace and Vanessa are a lot like each other. One tries to bust her brothers for their Big Ideas, while the other tries to bust her dad for being evil. They both are stunned when they fail, and constantly try every day, but fail. They often meet up with each other often and work together to succeed to their busting goals. ("I Scream, You Scream", "Hail Doofania!", "The Doonkleberry Imperative)"

A lot of their relationship is unknown so far, as they don't meet up with each other often. However, they meet on occasions and adventures when trying to bust their relatives. ("S'Winter", "Phineas and Ferb Summer Belongs to You!")

Moments of their friendship

 * Candace and Vanessa talk to each other on the ski lift. Vanessa tells Candace she should spend an hour with her dad sometimes. ("S'Winter")
 * Candace and Vanessa sing a duet about busting their relatives. However, when they fail, they are both stunned at the same time. ("I Scream, You Scream")
 * Candace accidently switches her clothes with Vanessa while going on a trip with her mom and Vanessa trying to bust Doofenshmirtz. They later see each other at the dry cleaners and realize what happened, replying "Hey!" ("Hail Doofania!")
 * Vanessa joins Candace for the flight around the world. ("Phineas and Ferb Summer Belongs to You!")
 * Candace goes to see Vanessa at Doofenshmirtz Evil Inc. Vanessa shows her the many inators her dad made, and Candace uses them to bust her brothers. ("The Doonkleberry Imperative")