Slave Vessel

Theo is a young man who attends an art school aspiring to become a successful painter. Betrayed by his respected teacher, he awakened to find himself on a slave ship, a "prison on the sea". If he can't escape, he will be a slave for the rest of his life. Together with his friend Kai who was brought in with him, he'll risk everything he has to escape from this hell. For the sake of freedom, he must deceive his enemies.

(Source: Kodansha, translated)