Krillin trained at the Orin Temple from the age 4, but was bullied by the older member and left to seek out the legendary Master Roshi. Krillin knows the type of person Master Roshi is and uses that to get him to accept him. He is cunning, but a jerk in the early days and sees Goku as a rival. At first thinking he is better and trying to show off. Through their time training Goku and Krillin become close friends though.