Kami no Mushi

The name of the island is Japanese for "Insect of god" or "divine insect". If you have found the testing area in Ninjinia, then you'll easily be able to find the one on this island.

Testing Area

You will need to have learned 850 Kanji to get though. For your trouble you will find a treasure chest that contains a headdress, an important Kabu relic.