@startuml

autonumber
actor "Receptionist" as R

activate R
R -> ":System" : asks to register an SNSUser
activate ":System"
":System" --> R : requests data (user's name, user's email, user's password,\n role id associated with an SNS user)
deactivate ":System"

R -> ":System" : types requested data
activate ":System"
":System" --> R : Asks for confirmation
deactivate ":System"
R -> ":System" : confirms data
activate ":System"
":System" --> R : informs operation success
deactivate ":System"

deactivate R

@enduml