Kensuke is an elderly Japanese man who has lived alone on the island for decades after surviving the bombing of Nagasaki. As a mentor and companion to Michael, he shares his wisdom and helps protect the island's wildlife.

Michael’s parents are a supportive and loving couple who embark on a global sailing trip aboard the Peggy Sue with their son. Their complementary traits and resilience help them face challenges together during their journey.

The poachers are men who come to the island to hunt animals, representing a threat to its wildlife. They serve as antagonists whose actions indirectly impact Michael’s relationship with Kensuke and the resolution of the story.