Seizansō (青山荘 Seizansō) is the name of the Mayaka Ibara's family inn. It appears for first time in Episode 7. It's located in the Zaizen village near the hot springs where members of the Classics Club spend their holiday.
Seizansō is built in traditional Japanese style and has a U-shape. It consists of 3 parts: the main building (reception, the refectory and the laundry) and the two others buildings, where guest rooms are located. However, the second floor of one building is unused due to the "Room No. 7 mystery". This floor is now used for storage.