Do you know Tokyo has some islands?
八丈島 Hachijo-jima island is also one of the islands in Tokyo.
In the Edo period, it was the territory of Bakufu directly that's why Tokyo has some islands even now.
It was also used as penal colony so some cultures were brought by prisoners and officers from all over Japan. For example, 焼酎 Shochu, it is called as 島酒 Shimazake in Hachijo-jima island.
Hachijo-jima has many beautiful view point. You can see many beautiful ocean views.
And Hachijo-jima is located in Japan Current, so you can eat very delicious fishes and enjoy diving.
