Even though he has a great circle of friends, Kaj  suffers from low self esteem due to being single, unemployed, and still living with his dad, Max,  who adopted and raised him from childhood after the death of his parents.  Max has been training Kaj to fight since he was strong enough to wield a sword for self defense. Why a sword and not a gun? Max never really answers the question. Kaj loves his dad, but for years he hasn't been able to shake the feeling that he's hiding something.