近未来…。日本政府は有史以前より国土に眠る新エネルギーΨ（プシー）の独自開発に成功した。さまざまな勢力から狙われるΨの秘密を守るため、サクヤ、ゴート、レオンからなる特殊部隊”ケルベロス”がその任務にあたっていた。最強の戦士は、銀髪の美少女サクヤ。 心にトラウマを持つサクヤを支えるのは、同じチームのゴートとレオン。 強いサクヤも弱いサクヤも認め、同じ仲間としてともに戦う。

In the the near future, the Japanese government has succeeded in discovering and monopolizing a new form of energy known as Ψ (“Psi”). To protect this precious new energy form rival forces, the Japanese government created a three-man elite force known as “Cerberus.” This team consists of: the “Princess” Sakuya, Gotou, and Leon. Gotou and Leon support Sakuya, who experienced a traumatizing past that still haunts her daily. Yet, she is the deadliest fighter out of the three.