We use Japanese or English for tours depending on which language you use. For canoeing tours, especially, our "one tour = one language" policy is strongly implemented. This is for us to assure communicating on water when sudden wether/lake condition changes.
You could reserve our tour based on "first come, first served" rule. For example, when English-speaking guest reserve one tour, then that tour is guided in Enlgish. And, next guest we accept for this particular tour is another "English-speaking-guest". Same rule applies for Japanese speaking tours. We may suggest another tour time/date, or decline your request due to above reason.