A mathematics genius girl, Nina Machida, starts in a new school and attempts to find her elder sister, who vanished from that school one year ago.

• Reina Tanaka
• Sayumi Michishige
• Dori Sakurada
• Haruka Kudo
• Masaki Sato
• Haruna Iikubo
• Ayumi Ishida
• Mizuki Fukumura