Dragon Ball Z Budokai HD Collection

This will unlock once you've completed the training exercises with Goku when travelling to Namek and after clearing "Let's Go To Namek!"
It will pop after you've completed the last exercise which is using your remaining health to defeat fake Vegata.

This achievement is story related and cannot be missed.

This achievement is earned during your travels to Planet Namek. During this time you'll engage in training session as you unlock some abilities and even learn some new fighting techniques. And then you'll put them to the test against the CPU of Vegeta.

Upon completing your last training session you'll pop this achievement and earn 15G!