Aika Tsube

Aika Tsube (津辺 愛香, Tsube Aika)/Tail Blue (テイルブルー, Teiru Burū) is one of the heroines/lead characters of Ore, Twintail ni Narimasu series. She is a 15-year-old freshman of Yōgetsu Private Academy and the childhood best friend of Sōji Mitsuka whom she treats like a little brother and she is rather overprotective of him, although this is later discovered to be because of her massive crush on him. Aika has a complex with her body, especially with her flat chest. She has a violent attitude toward Twoerle who often teases her about her chest. When she first became a Twintail warrior, she was mostly hated by the public, until later when Tail Yellow joins the team. In battle, Aika has an outstanding ability to fight as she was raised by her grandfather with martial arts. She is known as Tail Blue when she transforms, and her weapon is Spear of Water, Wave Lance (水の槍ウェイブランス, Mizu no Yari Weibu Ransu).

In Vol 8, she gains Eternal Chain.

Appearance
Aika is a 157 cm (5'1") girl with thigh-length dark blue hair that is styled into twin-tails with two white ribbons on either side and red eyes.

In the 16th volume, Aika is transformed into a little girl similar to Tail Red.

Personality
Aika has the personality of a normal high school student and she is by far the most down-to-earth member of the main cast as she is often finding herself speechless before the ridiculous antics happening around her and takes more time than anyone in the Twintail Club to accept the supernatural elements appearing in her world, leading her to become the 'straight man' of the group.

She is also pretty abrasive when she feels that her position with Sōji Mitsuka is threatened when Thouars is doing something 'stupid' (sometimes both at the same time) or provoking her for her flat-chest in both civilian and tail forms, resorting to violence and threats against the perpetrator.

She harbors feelings for Sōji and often displays this in a tsundere fashion. When she was hypnotized she even had an erotic vision of being in bed with him. She is often prone to jealousy when he interacts with other girls and was even downhearted learning Sōji got engaged.

Powers and Abilities
Aika's weapon is Wave Lance and her deathblow is Execute Wave.

Back when she was younger, Aika learned martial arts from her grandfather, and her main ability is to attack high places from even the lowest grounds. She gained the Tail Gear and can transform into Tail Blue (テイルブルー) the time Sōji gained his power.

Eternal Chain
Aika's Chain form as Tail Blue where she gains more armor and an increase in power.

Sōji Mitsuka
Sōji is Aika's childhood friend - both live in rooms facing each other. They are able to talk without trouble, although it has been hinted that Aika has feelings for Sōji, in which the latter doesn't seem to realize.

Etymology

 * The name Aika means "love, affection" (愛) (ai) and "fragrance, fragrant" (香) (ka).
 * Aika's surname Tsube means "haven, port, harbor, ferry" (津) (tsu) and "environs, boundary, border, vicinity" (辺) (be).

Trivia

 * Aika's birthday is August 8.
 * In Episode 1, it is hinted that Aika's favorite food is curry.