There are several trails and the easiest one to find is located across from the international villa. There are stunning views from various lookout points on the hiking course and the only things you are likely to run into are possible spiders in the forests. Other than that, it is peaceful and serene. There are two temples on the island and one is a very unique Thai-style one which is called Bussharito and is said to actually contain some of the ashes of Buddha. The other temple is called Kairyuji Temple and is located near to Bussharito. A beautiful garden is next to Kairyuji Temple and is a great place to relax and take a break after your hike. During the summer time, there is a beach bar called the Moooo! Bar run by a foreign couple, an Australian and an American. They can arrange motorboat trips to other islands in the Seto Inland Sea to take you to places rarely seen by tourists. The beach bar is open all day until sunset for cocktails, beer, wine, milkshakes, and various snacks. They sell beach wear, sunscreen, and even books in case you forget yours back at home. You can even get a massage on the beach for only 3000 yen for one hour. Now when have you seen prices like that on the mainland?
All in all, Shiraishi was a wonderful place to relax and to escape the city. From Osaka, just take a train to Okayama, then another train to Kasaoka, where you will take a ferry to Shiraishi. If you choose to take limited express trains and save some money, you can get there with under 5,000 yen. Much cheaper than a plane ticket to Okinawa.