A rōnin (浪人) was a samurai with no lord or master during the feudal period (1185–1868) of Japan. A samurai became masterless from the death or fall of his master, or after the loss of his master's favor or privilege.
The 10th Planet Ronin Tshirt was made to honor the 10th Planet Warriors who are far from a 10th Planet gym, but train the system and remain loyal. The red circle on the front and rising sun on the back honor the flag of Japan. The kanji characters mean Ronin.