Japanese love BBQ. Not like Czech people, Japanese grill meat, sausage, seafood and vegetables.
Then, usually Czech enjoy BBQ at their home backyards, Japanese enjoy BBQ at river banks, parks and even designated places for BBQ.
There are many BBQ spots run by the private firms around Japan. Then, the season of BBQ starts quite early, starting in April and ending in November.
These places rent the BBQ sets for affordable prices. Therefore you do not have to bring from your home and rent at the spot. Also the staffs will clean the grills and the utensils which you used. Then, handle the wastes. Therefore you have to just put the wastes, garbage to the designated plastic bags and hand over them to the staffs when you leave the premises.
Usually you have to bring your food and beverage, but there companies who deliver the ingredients and beverage to the designated BBQ spots. The procedure will be the same if you buy your groceries online. Just instead of your home address, you have to input the address of the BBQ spot.
If you are in Japan and encounters to BBQ, just bring some beers with you and the Japanese who are enjoying the BBQ will let you to join the BBQ there.