Arata Endo designed the auditorium in the south of the site, and its construction was completed in 1927. Parents of the 5th graduates from regular course proposed a plan of allocating the site used as the tennis ground to build the new auditorium, because the hall at the central building became too small to accommodate a growing number of students at that time. 　 　Full-scale repair work of the auditorium was conducted from 1989, including maintenance work of the eaves, the entrance, the drips and the fittings. After the construction work was finished, the auditorium and other three buildings were designated as Important Cultural Properties in May 1997. Conservation and restoration work was commenced in 1999, when we implemented quality air-conditioning facilities so that the buildings were to be utilized in the future. The auditorium currently functions as a place for concerts, lectures and weddings.