Undercover agent Sara has overcome numerous cases alongside her partner Hikari. However, one day she decides to infiltrate an enemy organization alone. When Sara finds herself in a life-threatening situation, Hikari rescues her—but something feels off. Sara's expression appears strangely emotionless, and she refuses to explain what happened. A subtle rift forms between the two women, yet they are soon forced to carry out another joint infiltration mission. As they face danger together, their strained relationship and the outcome of the case hang in the balance.