Liberal Arts City Arc

The Liberal Arts City or Arts and Sciences City  is a story arc that occurs between the Sisters Arc and the Daihasei Festival Arc. It is contained in the Toaru Kagaku no Railgun SS: Liberal Arts City Light Novel.

Trivia
Saten Ruiko and Xochitl meet for the first time in this arc. Xochitl is in disguise when they meet again, in the Daihasei Festival Arc, so Saten doesn't really recognize her.