It is highly recommended to include at least one day of stay at a ryokan, Japanese traditional inn. Supported with well-mannered Japanese style hospitality, a ryokan stay experience would give you a kaiseki cuisine (traditional multi course meal), a fantastic nature view from room, a bathe in natural hot spring, if not always. Sleeping in futon (mattress laid on floor) can sometimes too much of a cultural difference, but a Japanese room with a western bed can be arranged too.