If you are asked about things you do not know well, tell guests honestly that you are not familiar with them and cannot answer in detail. Guides of TOMODACHI GUIDE are not professional guides. They are simply people who want guests to experience what they usually do and love doing.
With that being said, they will of course have something they are not good at or lacking in the information department. Mitigate any possible trouble by not comprimising and start telling things that are untrue about yourself. Of course, it is necessary to make efforts for your guests. However, even in that case, you would be better off teling your guests that you are not familiar with their request. State your say reason and be polite, your guest will surely understand.