This is very interesting. Come to think of it, demands on knife's sharpness should vary up to the situation. The use at home & at the restaurant by the professional are to be different. Mr. Hayashi's point of view for home use is attentive & practical. The sharper, the better, which may not always be the case. So, a contrast of these two masters' interactions deserve much attention. This is a gorgeous trial! Well done!
From the sound of cutting paper at the final part, I guess the Master prefers a toothy edge, which is suitable to cut through thick, slippery skins of green peppers or purple aubergines. Very interesting.