After the shogun called for criminals to acquire the Elixir of Life from the dangerous island known as Kotaku, in exchange for a pardon for their past crimes, Eizen joined in the expedition team as one of the Yamada Asaemon monitors and was assigned to keep watch over the criminal, Rokurōta.
Eizen had long spiky red hair and wears a large eyepatch that covered his missing left eye. He wore a dark haori underneath the standard attire of a Asaemon, which is a white robe with a bell tied to the left collar and a hakama held together by a waist-cord.
When he was younger, Eizen's hair was much shorter and wore a different eyepatch at the time.
Eizen had great pride for the Yamada clan and believed that no task was impossible for them when it came to executing people, such as his assigned criminal Rokurōta. As an executioner, Eizen acted professional in his line of work as he knew that defiling the execution grounds by trying to bring pain to the condemned with his blade would defile the magistrate and followed the Yamada clan's ideal way of ending lives by cutting his victims with no pain or emotion, a concept which he tried to impart to a young Shugen. To this extent, he found it atrocious at how Gabimaru dealt with the criminals in the death match. Eizen was also kind and caring as he promised to look after Shugen when he was young, which brought a great influence to him in the present.
Like his fellow clansmen, Eizen believed that women in the Yamada clan should not follow the path of a samurai, which caused him to have an antagonistic relationship with Sagiri. He was fully aware of Sagiri's hidden fear of taking the life of another and tried using this to discourage her from taking on the shogun's mission. Eizen also bluntly told her to her face that as a woman she was not suited to become an executioner and that her place was to live a comfortable life within the household. Despite his disapproval, Eizen did try to look after her as he attempted to protect her from a few convicted criminals that targeted her (though this may have been because of his doubt that she could handle killing them).
Eizen, along with other members of the Yamada clan, stand on guard as the gathered criminals are told in detail about the mission to capture the Elixir of Life for the shogun. When one of them declined the mission, Eizen comes in to cut off his head since refusal of the mission was not an option. After the criminals were told to start a massacre in order to lower the number of participants, Eizen tries to discourage Sagiri from taking on the mission and bluntly stated that he disapproves of her being an Asaemon since she is a female. After the killing ended, Eizen got assigned to watch over Rokurōta and departed to the island.
As Rokurōta was being transported, the helping staff was wondering if he was as dangerous as the villagers said and worried about him waking up. Eizen assured them to not worry since he stated that the Asaemons were well suited for jobs such as this. After arriving, Rokurōta awakens from his sleep and was beginning to feel hungry. Seeing Rokurōta about to attack, Eizen tries to intercept it but fails and is ultimately crushed by Rokurōta's hand.
Eizen had a profound influence on Shugen as he was the one person the young man looked up to the most. Before leaving to Kotaku, Eizen promised Shugen that he would report back on the second day, causing him to become suspicious of his time on the island after three days had passed and cried in his absence. Shugen later went on to make it his goal of having Eizen and the other Asaemons return home in one piece after being order by the shogun to journey off to the island with a second team. After arriving on the island, Shugen becomes devastated after finding Eizen's corpse and took the time to lay his soul to rest despite the fact that his team was being under attack by Mōnshin. Eizen's death went on to impact Shugen on his mission as he vowed to kill all monsters and criminals on the island to avenge his fallen master.
Abilities and Powers
Being the first ranked Yamada Asaemon, Eizen was undoubtedly strong and the most likely candidate to become the next suitable head of the clan. Though he was given the first rank, Eizen was noted to have very poor combat skills and was not viewed as the clan's strongest member, a title that was rightfully earned by his protégé, Yamada Asaemon Shugen. Due to the nature of the hierarchy within the Yamada clan, which focuses less on a member's abilities, Eizen was given the first rank due to having outstanding qualifications for becoming the next head of the clan.
- Further information: Tameshi Ittō-ryū
As an Asaemon, he had the capabilities of decapitating a person with a single cut of his sword.
As an executioner, Eizen carried his own katana.
- Eizen ranked 17th place in the manga 1st Character Popularity Poll.
- In the Jigokuraku Fashion Review of Volume 1, Eizen and Kishō's attires were given 1 out of 3 stars.
- According to Jigokuraku Kaitai Shinsho, Eizen lost his left eye due to an illness during infancy.
- Eizen's hobbies were visiting shrines and temples.
- Top 8 popular male characters according to the Jigokuraku Kaitai Shinsho Q&A: Shugen > Tōma > Jikka > Eizen > Tenza > Fuchi > Shion > Kishō
- Jigokuraku Kaitai Shinsho, page 46