Gender: Female Known by the code name "Raijin," she is a member of the Goryojin, the organization's strongest five-man cell. Though only 16, she is one of the strongest in the organization. She is so quiet it is hard to tell if she has emotions. She wields a katana with god-like speed. She handles everything else with equal efficiency. When people speak of the strongest in Hydra, they speak of Raijin.

Gender: Male Known by the code name "Zeus," he is a member of the Goryojin, the organization's strongest five-man cell. He was personally trained by Kamikaze, another member of the Goryojin, and can utilize Kamikaze's techniques. He is called Hydra's greatest masterpiece in the shadows. Age: 23

Gender: Male Known by the code name "Kamikaze," he is a member of the Goryojin, the organization's strongest five-man cell. As a founding member and the President of Hydra, he possesses overwhelming power. He is often called "Shorty" by the members and snaps every time he hears it. After all, he is 31 years old despite his appearance. He is also the master who trained Zeus, Raijin, Bartory, and Shinon-Doji.

Gender: Male Known by the code name "Shinon-Doji," he is a member of the Goryojin, the organization's strongest five-man cell, and was considered the strongest among them. He was the original "strongest" before Raijin. He received Kamikaze's teachings and eventually surpassed him. However, he has since left the organization and now works as an office employee. The reason he quit being an assassin is that he has a younger sister who was also raised as an assassin; seeing her constant suffering, he decided to leave with her for her sake. Before leaving, he fought Kamikaze head-on and defeated him. Age: 27

Known by the code name "Bartory." He excels at cross-dressing and is incredibly powerful. He is one of those personally trained by Kamikaze, but he possesses a deep madness. He uses scissors as weapons and practices Mantis Style kung fu. Above all, he is a hedonistic killer who finds joy in torture. Because of this insanity, Bartory was imprisoned in a cell deep in the organization's basement. He was originally a candidate for the Goryojin. He is currently managed by Raijin, Zeus, and Kamikaze. Gender: Male

Gender: Female Known by the code name "Atlach-Nacha," she is a member of the Goryojin, the organization's strongest five-man cell. While she is a member of the Goryojin, her pure combat skills are the lowest among the five, but she has a vast repertoire of tricks and is highly intelligent. However, she only joined the Goryojin to fill the vacancy left by Bartory, and her reputation among members like Raijin and Zeus is low.

Gender: Male. A poison user. He is highly skilled in handling toxins and applies them to the tips of his knives. He can hold his own in a knife fight. He is one of Hydra's young aces. He looks up to Zeus as an older brother. Since the poison carries risks for himself as well, he only uses it when backed into a corner. Age: 12

Gender: Female She specializes in the Japanese sword, but she started as a talentless failure who couldn't do anything. However, after being taught by Raijin, she became a promising young prospect. She reveres Raijin as her master. Age: 12

She is jealous of her older sister Atlach-Nacha's success. She specializes in handling traps.