Yuuka Amado (雨渡 穣華 Amado Yuuka) is the treasurer of the Student Council Security Division, a senior at Tenbi Academy, and one of the supporting characters of the Maken-Ki! series. She is the young sister Takeru's homeroom teacher, Tomiko Amado and comes from a family of ninja's that specialize in espionage and ninpou. Yuuka is best friend's with the Security Division's president, Furan Takaki and is implied to be a lesbian that holds romantic feelings for her.
Yuuka appears to be carefree most of the time, teasing Furan a lot (mainly displaying her underwear); however, she is very cunning, mostly encouraging activities of the Maken-Ki that involve some kind of other work that needs to be done. The most obvious of these actions is the "match" between Venus and Maken-ki, where the players use broomsticks and soap while playing in the pool (using the grudge match to clean the pool). She also creates rules such that it would be unlikely that either side would win the match, as Akaya Kodai realises.
She later reveals that for many generations, the Amado family has been serving the Rokujou's as their oniwaban (ninja).
She is next seen upon Venus' arrival at Tenbi, introducing the new members to Maken-Ki. When Azuki Shinatsu and Yan Min wish to duel, Yuuka deflects the grudge into a match, claiming that Maken-Ki members are banned from duelling each other. However, Yuuka's rules for the game result in managing to score until the final moment, at which point Yuuka declares a draw (claiming only half the puck went in and Azuki's underwear stealing move was in a grey area).
Furan Takaki scolds Yuuka for manipulating everyone again, saying things will get complicated again, to which Yuuka replies that she is looking forward to it and laughs.
She then terrifies everyone in Maken-Ki/Venus by throwing knives at them when they are being noisy during a Maken-Ki meeting. This makes Furan laugh and comment that she can't compare to Yuuka.
Makaru - takes the shape of a earring that when brandished, can call back a soul even from the underworld and resurrect the dead. It can heal injuries, and allow the mind and soul to replenish at a speed suitable for the host's powers. It's the most striking of all the Maken. It is one of the original eight Maken, along with Haruko Amaya's Murakumo, Inaho Kushiya's Kamudo and Furan Takaki's Habaya.