Jansen is the master of a Buddhist ashram. He came to the ashram when he was young, after fighting in war, to find peace.
Oliver Queen studied briefly under him and Connor Hawke studied for five years under him.
Later, Jansen loses the ashram to a man named Fritz Mueller, who turns it into a moneymaking business, through training people in martial arts and selling prayers. Connor attempts to reclaim it but is defeated by Silver Monkey. After losing the ashram, Jansen accompanies Connor to Connor's grandfather's farm in Idaho. Then, he accompanies Connor to San Francisco. He becomes friends with Eddie Fyers while there.
Eventually, Jansen is able to return to the ashram, when Connor defeats Seljuk, who is Mueller's new chosen represenative in combat. Eddie and Connor join Jansen as his first new students at the ashram.