Shizuka is a very rational and selfish woman who prefers to act alone. A former accountant, she is adept at calculating risks and acts only for her own benefit. She is easily annoyed by the thoughtless actions of others and hates when things go wrong, a trait likely stemming from her abusive father who forced her to excel at everything. In person, she can seem cold and emotionally distant, often rolling her eyes at others' incompetence, but she is also observant and decisive, willing to take action to deal with a threat.