Sphere break is unlocked after completing the tutorial in Luca during chapter 2.
In the locker room hallway on the left side of Luca, there is a guy who is very easy to defeat. He has a quota of 20 in 15 turns, which is incredibly simple if you have an eco-bonus coin.
Here's the guy:
In Luca during chapter 3, you will have to win 4 Sphere Break matches to win the "Lady Luck" dress sphere, so I waited until chapter 3 to do this achievement. You are given several coins for this tournament; more than enough for the achievement. For the tournament, look for people with low difficulty stars and save after each victory. After you have won the tournament, go to the locker room on the left side of Luca and repeatedly beat the man there with a quota of 20 in 15 turns to get the achievement. With eco bonuses, you can win in 3-5 turns easily. I took coins of values 1, 2, 5, & 6 in (6 was my eco-bonus coin) and used 3 coins for each target. Try to use 1 center coin & 2 border coins for each match, but your primary focus should be keeping the eco bonus the same.
If you have any questions, please ask in the comments. If you negative vote, please say why so I can fix the issue.