The game's protagonist Senel Coolidge, who has mastered a special technique known as Claw Arts, is riding a small boat together with his sister Shirley Fennes. Senel is a marine trooper and earns his living by fighting demons. His tendency to do things suddenly and without giving any explanations, has resulted in many misconceptions about his character. He is often perceived to be an unsociable fellow. After he unexpectedly arrives on the gigantic Ruin Boat, he is drawn into a struggle for the survival of his world.

28-year old peace officer Will Raynerd is the first person Senel meets upon arriving on the Ruin Ship. While Will is currently acting as sheriff of the Lighthouse Town Veltes, he is originally a natural history researcher.

Chloe Valens is a talented 17-year old warrior, yielding from a noble family of warriors. Her objectives are unknown, as she keeps the reason why she came to the Ruin Boat to herself. Norma Biatty is a 16-year old treasure hunter. She has boarded the Ruin Boat in order to find the Ever Light, a treasure that is said to grant all wishes. Moses Sandor has made himself a name on the Ruin Boat as head of a gang of bandits.