Liberal Arts City Arc

The Arts and Sciences City Arc or Liberal Arts City Arc is a (possibly non-canonical) story arc that occurs between the Sisters Arc and the Daihasei Festival Arc.

Trivia
Saten Ruiko and Xochitl meet in this arc and again later in the Daihasei Festival Arc (Railgun). But when they meet in the latter arc, they seem to have no recollection of each other. This suggests that the Arts and Sciences City Arc is non-canonical.