It's only logical to fix a malfunction, but Karasuba is offended that Haizakura suggested Nagi repair her.

A lost automata wanders into the path of the Black Cat’s staff, but who exactly is she? They’ve never seen a model quite like Haikagura before…

In the wake of disaster, Haikagura sleeps, and her origin remains a mystery. While Nagi investigates the mysterious automata, the other dolls prepare for the Capital Fair.