Kozu and Shikineshima were the best of the five islands. Remote and pristine, they offered mountains, hiking trails, beautiful beaches, natural hot springs, and delicious food.
Lodging for the night was the hostel-esque pension run by the Hasu family. Mrs. Hasu was born on Kozushima (you have to be a resident for several years to purchase property) and Mr. Hasu was a native of Tokyo who fell in love with the islands during his college years and ended up staying there. He runs their pension, which holds a maximum of ten people; his wife is an elementary school teacher by day and works at the pension by night. They have two children, a son who works in Tokyo and a daughter who is in her last year of high school.
Mr. Hasu was perhaps the friendliest person I met on the trip, who clearly loves the island and wants his guests to enjoy themselves. (And he doesn't hesitate to drive them around the island.) If you end up visiting, I'd highly recommend you stay at the Hasu family Pension, called KOHOKU. Book ahead by telephone and he'll pick you up at the port. Their number is 04992-8-0964.
At the northern tip of Kozushima is Akasaki, a rocky area where you can swim, snorkel, jump into the sea, and see the most spectacular scenery
With goggles, you can also go underwater and see the most amazing marine life -- squid, blowfish (fugu), coral, bright blue fish, and much more. I'm sure you could see far more diving, which is a major tourist attraction.
I had just five hours of Shikineshima, but being that the island is only four square kilometers with a population of barely 500, I saw almost all of the island.
Like Kozu, it was beautiful. Although significantly less mountainous, the beaches were magnificent.
The island has several shrines and temples -- here, a Torii gate is buried in the forest.
Here, a real highlight -- a natural hot spring right next to the Pacific Ocean! The rusty color makes the water look filthy in photographs, but it was quite pleasant.
Also of note: the entire pathway winding down the seaside cliff to the hot spring was brand new. The reason? As recently as 2002, waves reaching as high as 8 meters (26 feet) during a typhoon had destroyed the old route.
And not to beat a dead horse, but Shikine and Kozu really did have the best food of all the islands. Here you can see a dinner including fresh sashimi at the Hokoku pension, and below, the locally famous ashitaba leaves fried in Tempura batter. The meal is called "Shikine Teishoku" (Shikine Set Meal).