This is the sea of Yoron Island in Kagoshima Prefecture that I went to on my trip.
The sea is the most beautiful I have ever seen. There were almost no people and everywhere I went, it looked like a private beach. The sea was also wonderful, and I was able to see a lot of fish not only diving but also snorkeling. It has not been developed and there are some inconveniences, but it is also valuable and I wanted to leave it for future generations. I will never forget taking a leisurely nap on the nearby beach every day.