El Hazard: Les Mondes Alternatifs

Miz plans to retire as a Great Priestess of Water to married life with her darling Fujisawa and as replacement the young Qawoor Towles arrives to Floristica. Jinnai sees Qawoor's initiation ceremony as a chance to infiltrate Makoto's laboratory but accidentally activates a mysterious thingy that sends them all through the dimensions to a grey industrial city protected by a huge castle in an alternative world.

(Source: ANN)