What is a "PENSION" in Japan?

It is a Western-style accommodation facility that operates on a small scale usually with no more than 10 rooms. Almost all pensions are family owned and run.
  Most pensions are located in resort areas on a plateau or seaside and can be utilized throughout the four seasons. Usualluy, pensions in Japan serve Western-style meals for dinner and breakfast. After dinner, pension owner might invite guests to a communal room or game room to get better acquainted.

How to use these pension facilities.
Upon arriving at the pension, please take your shoes off at the entrance, and put on the slippers which are used for walking inside the pension (in the corridor, lobby, dining room and guest rooms). Some of the pensions do not have private bathrooms but have baths for common use. Please do not use soap in the tub, and do not pull out the plug.