Complete the following tasks to unlock the desired effect:
Be King in Free & versus Modes: complete story mode using Haru
Be Aniki in Free & versus Modes: complete story mode using Musica
Be Gale in Free & versus Modes: complete story mode using Shuda
Be Poosya in Free & versus Modes: complete story mode using Elie
Be Sieghart in Free & versus Modes: complete story mode using Go
Edit Your Own Story: complete story mode using all 5 default characters