There are many types of recreational vehicle in Europe, motorhome, campervan and caravan. On the other hand, caravan is not common in Japan, therefore recreational vehicle means campervan in Japan.
According to Japanese law, campervan must be equipped with kitchenette, height must be taller than 160 cm and at least 1/3 of passengers can sleep on flat beds. However, passenger should not lie down during the campervan in motion.
Campervan was a huge boom in 90s and it is now popular in Japan, due to camping is very popular especially during COVID-19 era. These campervans are based on Japanese vehicles and it is rather rented rather than owning a campervan. Therefore there are many companies which rent their campervans for short term and long term.