They were close even in middle school. Ayaka has been an outstanding photographer ever since. Saten was heterosexual, and Ayaka was bisexual, so the two were more than friends.
Saten followed Ayaka's future career as a photographer, and was more agile than Ayaka, so she was good at tracking down objects that primarily moved.
Their hobby was to take pictures and videos. However, enjoying collecting pantieshots of classmates was no different than before and now. The two have shared their roles with each other, and until this point they have had little trouble.
But one day, Ayakawa Saten witnessed a terrible thing.
The girls were lurking in the corner of the dark night alley to film inside the careless classmate's skirt.
Then something smash the classmate's head while he was hiding, and she fainted on the spot.
The fainting classmate was dragged back into the alley. They were surprised but did not discover their existence, and began to follow the mysterious beings who kidnapped their classmate.