Whitetip Reef Shark (Triaenodon obesus) is the only shark that I have been able to identify in Japan so far. In Hawaii they would usually rest in caves or under ledges in the day. In Japan I have seen them swimming in the day. I saw one resting in a sand patch. I have not seen any resting in caves so far in Japan. Amami
This Whitetip Reef Shark was a little curious and did a half circle around me. It also has a remora on its chest.