Krillin is Goku's friend who has spent the most time with him. He is also a disciple of Master Roshi, he appears for the first time in Chapter 25, in the beginning he is competing with Goku and is trying to beat him in dubious ways. But eventually they sympathize, and Krillin then will play an important role and lend a strong hand to Goku. He participated in combat against the Saiyans (Vegeta, Raditz) and against Frieza and his acolytes.

When Frieza kills Krillin, Goku wakes up to the power of Super Sayan.