A character introduced in Mahou Tsukai no Hako, and one of the mascots for TYPE-MOON's defunct mobile website of the same name. She has short orange hair with an ahoge and yellow eyes, and is usually seen wearing the Kagamisaki High School Uniform or the Ahnenerbe Shop Uniform.
She was originally the holy scripture Triten completed by the dead apostle Caubac Alcatraz in the year 1000 as his thesis on God's love. Triten ended up being a complete model of the universe, resulting in Caubac creating an inescapable labyrinth to protect it from the outside world. She inexplicably woke up one day as the human Hibiki, causing him to undergo a crisis of faith. As Hibiki, she identifies Caubac as her grandfather. Triten is genderless and has white hair.
She is playable in Fate/Grand Order alongside Katsuragi Chikagi as the Alter Ego Servant Azumi-no-Isora, introduced in Odoru Dragon Castle! event. In their Third Ascension, they become Sirius, due to Hibiki's identity as Triten.
Character Design: Takeuchi Takashi, Anmi
Voice Actress: Honda Youko