Number Member is a mysterious organization composed of different Numbers.
Each Member performs his or her own duties. They do not know each other's true identities and are only identified by their respective numbers.
Outsiders don't know the true meaning of this organization's existence.
The members of the group don't know how many companions they have, and they have never actually seen their King.
They just receive orders and execute them through mobile phones modified by the organization.
Seven, who lost her memory, was one of the NMs. When she regained consciousness, she found herself in the hospital.
Among her belongings was a mobile phone that looked ordinary but had obviously been modified inside.
And not long after she was discharged from the hospital, she received a call from an unknown number...