Thank you for your review. .. If you don't put music in, the video can get boring if it's too long, so I intentionally put in time and effort.. After receiving various opinions through a survey, we came to the conclusion that BGM is good, but volume adjustment is more important. So I re-produced it with the volume adjusted and uploaded it. And as you said, I think there may be some people who find BGM itself distracting from learning, so I'm creating a separate NoBGM. Thank you.