Raiko resembles to Raikō.
Raikou is portrayed as rather an easygoing, well-mannered person who takes his responsibilities very seriously. It is implied that he is a sadist, losing control when a target hurt Gau and repeatedly slashed through the corpse until blood spilled everywhere. He keeps his Shirogamon on his right hip, making him having to draw it with his left hand, this may imply that he's left handed. Even though, this doesn't seem to hinder him in battles as he still challenges Raimei with ease, making his left-handed swordmanship an advantage over others. After his second fight with Raimei, he left Shirogamon in the field of spider lillies, replacing it with a tri-sectioned staff, which he uses for 2 to 3 battles in particular. Afterwards, he picks up another, a katana, shown to be used in reverse-grip, in the same style he used to cut Raimei.
The offensive power of his Final Susanoo is comparable to that of a Eight Headed Dragon.
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When Raikou was fifteen, mutany within his family broke out against his mother, the leader of the Shimiza clan. His Uncle Hiroku disagreed with her ways, He wanted to use their ninja abilities to actively help people; while Raikou's mother thought that they should stay in the middle, and only intervene to help keep a natural balance. Raikou had originally agreed with his uncle because of an incident when a friend of his was in trouble and died because his mother forbade him from helping her. The Yamata no Orochi emerged went on a rampage and devoured seven of Kushinada Haruno's sisters. The only other members of the Shimiza family after this incident is Raikou's sister, Raimei Shimiza, who was only ten at the time. Awoken from sleep, Raimei stumbled upon a room full of her injured family members and her uncle, and only Raikou standing alive with his sword after Susanoo Uzumaki sealed the snake.
Raikou works as a punisher, cutting down those who betray the Akatsuki in the Wakachi with his partner, Gau Tamatari, a boy whom he rescued from death three years ago. Upon his victims, Raikou places spider lilies with the intent of luring Raimei to a field of spider lilies so that he could confront his younger sister later on. He chooses not to tell Raimei his motives behind the massacre to protect her innocence. This leads to a battle between the two, as Raimei finds it her job, as part of the Shimizu clan, to deliver judgement. In her eyes Raikou has soiled the Shimizu family name. She finds Raikou near where the Shimizu house once stood, the place where the red Spider Lillies grow. During this battle, Paul Gekko steps in saying En Garde you despicable snake. thus Raikou cuts both deep into Raimei and Paul and leaves them bleeding, and incapacitated in the rain, where he then leaves with her sword, Kurogamon. Later, he confides in his partner, and only real friend, Gau, after he is asked about his past. He tells Gau the whole truth, but makes him swear to secrecy, and makes it clear that there will have to be punishment if he doesn't keep his promise. However, Gau is deeply moved by the story and believes that Raikou and Raime should be brother and sister, not enemies. Tracking Raimei down, Gau tells her what happened 5 years before, holding a kunai to his throat and betting his life that it's true. Later, after she gets out of the hospital, Raimei goes forward to meet Raikou for a rematch. In the field of Spider Lillies, Raikou gives Kurogamon back, but quickly disarms Raimei anyway. Upset, Raimei lands a punch on Raikou, yelling at him for thinking her to be so weak and taking on the burden alone. Crying, she asks him to come home. He tells her that it is too late, and makes her take up her sword once more. Seeing characteristics of their mother in her, he attack Paul Gekko in his Full Orochi Mode only to find Gau, who in an attempt to intervene, takes Raikou's blow, the one meant for Raimei, saying "I came to accept my punishment." Gau then falls over bleeding, and instead of being angry, he begs for the two to stop fighting, and apologizes for breaking his promise not to tell Raimei as he slips under into comatose. This deeply distresses Raikou, his concern for Gau's condition runs so deep that he contemplates whether Gau will awaken or not, believing that he will not, due to thinking that Gau no longer wanted to see him again. With the Kuro Akatsuki defeated and the Eye of the Moon Plan ceased, Raikou became friends with Cassandra Uzumaki in the Gekko Clan.
- Paul Gekko- Adopted Older Brother
- Raimei Shimiza- Younger Sister
- Koutai Shimiza- Mother
- Houmai Shimiza- Father
- Hiroku- Uncle
- Taiki Shimiza- Son