Successfully complete the indicated Story mode chapter to unlock the corresponding artwork:

Concept Art 1: Jadow Stars: V-Puzzle 7
Concept Art 2: Jadow Villains: V-Puzzle 8
Concept Art 3: Gedow Stars: V-Puzzle 9
Concept Art 4: Gedow Villains: V-Puzzle 10
Concept Art 5: Main Villains: V-Puzzle 11
Concept Art 6: Main Stars: V-Puzzle 12