Publisher's Summary
"Such misfortune..."
Midsummer evening.
Kamijou Touma murmurs as the money he plans to spend on juice is swallowed by a vending machine after a long day of supplementary lessons.
"Wait a sec! What are you doing here?"
Accompanied by the tapping sound of a pair of loafers, Misaka Mikoto notices Kamijou Touma.
"Onee-sama?"
After that, a girl with the splitting image of Mikoto appears.
A meeting of three people.
This is the narrative of the events that happened within that incident.
With Accelerator called out, his slaughtering play begins again as nightfall opens up.