Marimo Moss Balls make great pets/companions. To keep a Marimo moss ball as a pet, all that is needed is a water change every couple of weeks. Marimos are truly unique and special! Did you know that they are native to Lake Akan in Hokkaido, Japan and are considered a national treasure in Japan. Even festivals are held each year in Japan to celebrate their charm and beauty. It is believed they bring good luck to their owners. Marimo moss ball terrariums make great graduation/birthday/office/bridal shower gifts!