In the manga and video game, Koganei has blue hair and blue eyes. He wears a white T-shirt with a vest over it, as well as shorts and sneakers. He wears different sorts of street clothes throughout the rest of the manga. Under a bandanna he wears tied around his right wrist is a suicide scar.
In the anime, he has brown hair and eyes, he wears a necklace with the similar color to Kogun Anki, and an attire similar to the manga and game.
Little is known of his early life, but given that in a manga flashback Kaoru was seen attempting to commit suicide, it can be assumed he was a lonely child until he met Kurei. Kaoru is the youngest member of Hokage, and as such, his personality reflects his age. Even in battle, Kaoru is playful, and sometimes has a tendency to toy with his opponents as if the battle were a game.
Part in Story
Kurei's Mansion Arc
He first appears to kidnap Yanagi, alongside Mokuren. After successfully doing so, he holds guard at Kurei's mansion, later fighting Tokiya Mikagami (the two of them gain a lot of respect for each other's respective skills following this battle).
Ura Butou Satsujin
Before the fight between Team Hokage and Team Uruha Maboroshi, Koganei joined Team Hokage because they are short of one member due to Fuko's inability to fight and to protect Yanagi, but Recca, Domon, and Mikagami still disapproves Koganeis proposal but allowed him to fight with Shiru. Koganei proves that he can fight very well and decided to fight again with Mukoren but is tricked and then trapped inside him and absorb his energy. Later, Kouganei is freed by Miyagi by defeating Mokuren. On the orund between Hokage and Uruha Ma, Koganei Fights against Tsukishiro who weilds two madogous, Oboro which makes him invisible and Kaigetsu. Before the finals, a mysteroius old man, which will be revealed as Kokou, in forms him about Kogan Ankis Sixth form, Mu but cannot tell how to do it because he "forgot" how to. Later that night Koganei persuades Saicho to come with him to check out the stage to be used but ends up with Saicho being severely wounded by Joker. On the finals, Koganei fights Joker to avenge Saicho. While fighting, Koganei experiences minor changes with Kougan Anki and thought that this was failed forms but later learns that Kougan Anko can create many other forms and because he uses shortcuts when changing Kougan Anki, he misses the true path on forming Mu so he formed Kougan Anki using the long way around starting with Kiba, then Ryu, then Kyoku, then Mikazuki and finally An. This leads to disassembling Kogan Anki making it "formless". Kogan then wraps the crystal ball holding Kogan Anki together around Joker and then reforming it making all the pieces pierce through Joker defeating him.
Sealed Lands Arc
In SODOM, Koganei's first real opponent was Gaou at the Biodome, who was still seeking revenge against Domon. However, Koganei managed to defeat Gaou. Later, he faced off against Z to get the last data disc, which he succeeded in doing. Inside Hell or Heaven, Koganei ran into Joker, who was seeking a rematch. However, the two end up pairing up against Kirito and her pet Shiguma. They both defeat Kirito, but Joker sacrifices himself to defeat Kadotsu, who had survived Kurei's attack. Koganei saves Kagerou from Mori Koran's minions, but is later overpowered as the main body comes out of the cocoon. At the end of the series he goes to live in the past with Kurei.
Koganei is amazingly athletic, able to outmanuever a genetically altered Shiju who has lion cells in his body. Kaoru's greatest ability is his quickness and agility.
Kōgan Anki (鋼金暗器 Golden Blade): Kougan Anki is a "puzzle madōgu". It is a bladed weapon that can change into six different forms, the last one being a hidden form. Its primary stone has the symbol gold/metal (金, kin/kane) written on it.
Koganei is very good at solving puzzles, and can transform Kougan Anki in 0.6 seconds, while it usually takes a skilled user 10 seconds to transform.
|Kōgan Anki (鋼金暗器 Golden Blade)|
|Kiba (牙 Fang)|
|The first, base stance of the Kōgon Anki is a large pole-arm type weapon, with grip-handles in the middle, and a large clubbing end on the bottom. Its the form that is often used by Koganei. The blade is a thicker version of the kind found on a naginata.|
|Ryū (龍 Dragon)|
|The second stance, The Chain-Sickle, or Kusari-Gama. It is a very potent weapon, capable of disrming, entrapping, or directly harming the enemy from a distance. Next to Kiba, its the other form Koganei oftenlly use.|
|Kyoku (極 Zenith)|
|The third stance of the Kōgon Anki, The Giant Scissors. Primarily a weapon made for disarm, against large opponents it can inflict massive wounds.|
|Mikazuki (三日月 Crescent Moon)|
|The fourth stance of the Kōgon Anki, The Boomerang. When thrown, the boomerang moves through the air so fast that it creates a buzzing noise. It returns to its users hands both after impact, or after a miss.|
|An (暗 Darkness)|
|The fifth stance of the Kōgon Anki, The Bow and Arrow. The arrows seem to have no apparent storage space, although they are made of the same red and gold material as the rest of the Kōgon Anki.|
|Mu (無 Nothing)|
|The illusionary sixth stance of the Kōgon Anki. When the Kōgon Anki enters all five of its forms quickly and in order, then the way to make it into Mu is revealed. When it is transformed into this stance, the weapon separates into dozens of pieces of the puzzle madōgu, including the main crystal, still attached to the chain. The crystal is thrown at the opponent, and when the user wills it, the Kōgon Anki attempts to re-form to the first stance, causing the bulk of it to pass violently through the opponent. This form was only seen in the manga due to the fact that the battle between Koganei and Joker was cut short at the animated series.|
- He is known as Lorkhan in the Filipino version of the anime.
- It's implied during Koganei's fight with Joker, that Kōgon Anki might have even more forms.
- In the manga, the Kōgan Anki was called a "magic golden staff". This is a reference to the chinese novel, Journey to the West. In the novel, one of the main characters, Sun Wukong, has a weapon that can change it's shape at will.
- In the English Dub of the anime during the Kurei Mansion arc, his voice as a kid has a high pitch tone until in the Ura Butou Satsujin arc, his voice changed into a teenage-like deeper voice. However, his voice is still Brett Bauer.