for your reference
here are the characters' twitter profile

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main characters
Rikka Eisha Villareal

Sean Rayden Montenilla

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Rikka's Circle
Seanna Ellizandria Montenilla

Jannela Cuervo

Minami Hashina Takahashi

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Sean's Circle
Hansel Keith Cervantes

Marxis Drei Del Mundo

Phoenix Cuervo