A goofy assassin suffering from amnesia. Before becoming a killer, he was selling beef offal with Dabao just because he heard it was profitable. He started the assassin business because it pays better and to save money to recover his memories in Stan, a technologically advanced nation. However, due to his kind nature, he isn't very good at killing, ranking 17,369th—nearly the bottom. He even failed his initial attempt to kill an animal. In short, he is a man of deep affection.

A blue broiler chicken who calls himself the Chicken King. He is Seven's friend and Xiao Fei's guardian. He is a remarkably smart chicken and demonstrates great technical skill, such as creating the Gai Ba Egg, a transformation item. Since he is tight on money, he constantly nags Seven to earn some and led him into the assassin business.

A female assassin from Xuanwu who suddenly appeared before Seven when he was in danger. She is a highly skilled fighter recognized even in Xuanwu, the land of assassins, but as she repeatedly fails to capture Seven, her relationship with him begins to grow closer.

A female member of the Shadow Assassins of Xuanwu with red hair mixed with white streaks. She absolutely hates having her appearance ruined.

The prince of the Stan Kingdom, which opposes Xuanwu. He conducts various experiments and technological research to win the war against Xuanwu. Perhaps because he is a scientist, his physical body is frail compared to martial artists, and he wears only underwear beneath his lab coat. However, he possesses superior technology and has modified his own body to withstand most fatal injuries.

Thirteen's older sister. Her assassin rank is 88th. Like Thirteen, she is presumed to have been abandoned by her father for being a daughter, and she harbors even greater hatred toward him than Thirteen does. She has a technique that allows wings to sprout from her back like an angel, enabling her to fly freely. She is skilled in disguise, throwing darts, and seduction, often using poisoned weapons.