Teruko, known as the "Masked Maid," is said to be invincible at short range combat and an expert at martial arts. Her prowess enables her to act as Iria Akagami's bodyguard. The youngest of the Chiga triplets, she is vastly different from her older kin. Though her sisters preform standard maid activities, Teruko rarely follows them in their duties. Whether she actually needs her glasses is ambiguous, though she does say she wears them to differentiate herself from her sisters, the truth of that statement is unknown, however. Out of all the triplets, Teruko has a silent demeanour, almost never letting a word come out of her mouth. When she does say something, anyone that hears about it is shocked to know that she spoke.

Spoiler

While Teruko escorts Ii to Kunagisa's room, she tells him that he, "should just die." During their conversation, Ii asks Teruko if she's lying, with her saying she is several times. When they stop conversing, Ii learns that Teruko is a chronic liar and rarely states the truth, which may be the reason for her lack of speaking.

As Teruko has incredible martial arts abilities, she is practically impossible to defeat in close quarters. Suited with a bulletproof maid outfit and a metal mask, inflicting damage upon her is a tough feat.

Spoiler

Teruko's prowess in fighting is shown when she fights Akane, where she mercilessly breaks her arm and several ribs among other injuries. Teruko also acts as a shield for Ii after Akane pulls out a gun, ensuring to protect a guest from harm, even when the bullet missed altogether.

Spoiler

After defeating Kishishiki Zerozaki, she is dubbed the, "Masked Maid," as she was wearing an iron mask while fighting him.