Sentai Filmworks has licensed the first three seasons and released the first series on DVD and Blu-ray in bilingual form.
The series began in 2007 and has run several short-run series with each working its own progression and theme while tied to the larger work.
The work comes from the property that deals with the alternate world setting from the Fate/stay night universe as written and illustrated by Hiroshi Hiroyama.
In a respite from the fighting, they all rest in the house Miyu and Shirō took care of.