Obito is a guardian spirit who has a contract with one of the guardians of the source of magic, Kakashi.

Obito realized that Kakashi considered weak physically and magically compared to his other brothers, therefore Obito had to protect him extra. Because Kakashi's brothers didn't like him and often bullied him.

Like now, Obito sees Kakashi getting bullied by his brothers' again, so Obito make them left his master. Then approach Kakashi.

"Master, are you okay?"