Siren is the absolute queen who administers the state of lakeside park city, which boasts a 99.9% safety and happiness rating. One day, one of the Ondine, the information terminals born from her, gets lost and helped by an uncouth boy named Len Kinami. Ondine feels a wamrth from Len, who complains as he pulls her hand along, but that emotion flows in to the queen, who becomes bewildered by the unknown feeling! "Happiness is our duty." The addictive song that has been replayed a double million times, brought to you by the pioneer of Miku trance, Utata P, has been comicalized, based on the novel written by Tory Hitsuji!!

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  Siren

  The absolute queen who administers the state of lakeside park city. Queen Siren is the Thinker that transcends an AI. She charms and controls all her citizens through a song about happiness and peace of mind.
  

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  Ondine

  One of Siren's living information terminals. She's like an avatar who transits what she experiences to the queen.

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  Kühleborn

  A Grand Chamberlain, executioner, and clown who works for Siren. Likes ice, and is very elusive.
  

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  Len Kinami

  The student inter cadet of the happiness and peace of mind committee. He likes to take things at his own pace and never holds back toward anyone.