He's what you get if you cross a possum with a Higgs Boson accelerator.

Amonsun the Karutan House Pet is one the deuteragonists of both the movie and the series of the Battle Day/Exchange Student Zero Saga.


He is ridiculously cute while dormant, but possesses the ability to morph into a fearsome fighting machine that can take on many forms. As Hiro's loyal pet, he takes his job very seriously.

Powers and Abilities

  • Intangibility (movie only)
  • Transmutation (series only)
  • Flight
  • Laser Vision
  • Cuteness Inducement
  • Supernaturally Dense Tissue
  • Supernatural Intelligence
    • Mystical Martial Arts
    • Mechanical Intuition



He has served and protected the Karutas since Hiro's infancy. For years he has remained loyal to the royal family especially to Hiro. Despite the numerous struggles they both faced or how ridiculous his master orders him, they are even closer than just hero and sidekick.


In "His Life as a Dog", it was revealed he had a calendar of Felintine possibly having an interest on her.

In "Amonsun Under Fire", they personally met inside the dojo during a sparring session. However, it ended with a draw and him stretching her face wide. They are likely to be friends or neutral to each other.

Unnamed Malentwine

In "Dead Cute", he developed an romantic interest towards a Malentwine summoned by Max. He tried flirting with it but gets knocked out by doing so, when it multiplied he loved all of them anyway, even when almost all of them merged into a Mega Malentwine. When he finally saw the last of them, he quickly captures it, makes out and makes more it.


Click here to view the gallery.


  • He has served Hiro for more than 500 Karutan years.
  • He is allowed to eat on the table at the Stitt household.
  • He sleeps inside a drawer where he has his own bed and calendar.