TV-Series
Description
Kyoshiro Mibu is a central figure in the narrative, sharing a body with the legendary warrior Demon Eyes Kyo. He initially presents himself as a peaceful, somewhat bumbling and cowardly medicine peddler who travels the countryside selling dubious remedies. This gentle facade, complete with a kind heart and a strong aversion to violence and killing, stands in stark contrast to the ferocious reputation of the demon residing within him. As a kind and caring individual, he often becomes the source of comic relief alongside the headstrong Yuya Shiina, appearing more interested in avoiding conflict than engaging in it.

However, this gentle personality is a mask hiding a deeply complex and tragic past. Kyoshiro was not always a wandering medicine seller; he was once a high-ranking member of the Mibu clan, a powerful and secretive group. He was one of the Red Cross Knights, created from the flesh and blood of the former Crimson King, and was groomed to be a fearsome assassin known as the Demon-God. In fact, it is revealed that he is the true Thousand Man Killer and the only swordsman to have ever defeated Demon Eyes Kyo in battle. His skill with a sword is considered equal to Kyo's, and he is a master of the Mumyo Jinpu Ryuu Satsujin Ken, the same deadly sword style.

Driven by a desire to protect a young shrine maiden named Sakuya, with whom he was deeply in love, Kyoshiro abandoned the Mibu clan. His past is marred by the assassinations he committed under the clan's orders, including the murder of Shiina Nozomu, the older brother of Yuya Shiina. Kyoshiro killed Nozomu after being falsely led to believe he was an assassin sent to kill Sakuya, an act witnessed by a young Yuya and the source of her quest for revenge. Consumed by guilt over this and other violent acts, Kyoshiro took a vow to never kill again, which is the primary reason for his peaceful wanderer lifestyle.

Kyoshiro's most significant action was his fight with Demon Eyes Kyo at the Battle of Sekigahara. Unable to bring himself to kill his rival, who was also a close friend, Kyoshiro instead sealed Kyo's soul within his own body and hid Kyo's original form elsewhere. Throughout the story, his role is that of a hidden mastermind, orchestrating events from behind the scenes. His ultimate goal is not just to protect Sakuya, but to ensure that Kyo, as a member of the true Mibu clan, grows strong enough to defeat the tyrannical former Crimson King, a foe that Kyoshiro, as a Red Cross Knight, is unable to destroy himself. His motivations are largely selfless, driven by a need to atone for his past sins and to safeguard those he cares for.

His key relationships are the core of his character development. His bond with Kyo transcends rivalry; they are deep friends who respect one another's strength, even as they are forced to inhabit the same body. His love for Sakuya is his primary motivation, while his relationship with Yuya evolves from one of accidental adversary to one of deep care and protection, as he seeks to make amends for killing her brother. Throughout the narrative, Kyoshiro demonstrates tremendous growth, finally confronting his past and the trauma that has haunted him. In the final arc, he hatches a plan to sacrifice himself to help Kyo achieve victory, proving his compassion and heroism. Ultimately, he survives and finds peace, living with Sakuya while maintaining a friendship with Kyo and Yuya.

Kyoshiro is an extraordinarily powerful fighter. Despite his vow of pacifism, when he does take up the sword, he demonstrates overwhelming skill. His mastery of the Mumyo Jinpu Ryuu includes devastating techniques such as Mizuchi, which launches a deadly cutting wind; Shinkiro, which creates powerful visual illusions; and the Ougi techniques based on the Four Symbols, including Suzaku (a flaming phoenix), Byakko (a white tiger), Genbu (a tortoise for defense), and Seiryuu (a dragon whirlwind). He also possesses unique abilities like Soul Transfer, the very technique he used to seal Kyo's soul, and he was the original owner of the demon sword Shibien, which turned black from the immense number of lives it took.