Juugo Shounen Hyouryuuki

Fifteen students board a vessel intended to transport them to family members in New Zealand, but the boat loses its anchor and drifts into the open ocean during the night with no crew aboard. A storm the next morning blocks their return to port, and several days later, the boat runs aground on a remote Pacific island. Over the next 20 months, the children must organize themselves to survive, including gathering supplies for an approaching winter. Briant, Doniphan, and Gordon take leadership roles as the group discovers evidence of a sailor who had lived and died on the island two decades earlier.