They are called "ライダーハウス" (riders' houses) and there is [https://ja.wikipedia.org/wiki/%E3%83%A9%E3%82%A4%E3%83%80%E3%83%BC%E3%83%8F%E3%82%A6%E3%82%B9 an article on the Japanese Wikipedia], but so far I can find very little information in English.
We could benefit cyclists and people who must or who enjoy travelling on very low budgets if we can find some information on these to include. — [[User:Hippietrail|Hippietrail]] ([[User talk:Hippietrail|talk]]) 0104:4134, 9 May 2014 (UTCCEST)