Chibi are agents of Satan who dwell the surface world seeking hosts to infect with his will. This is accomplished by deceiving mortals with their endearing appearances, often in the form of a loved one or famed figure. They maintain a facade of love and devotion until their host is completely obsessed, at which point the chibi infects the host, who is used to aid Hell's forces, imbued with demonic abilities. However, the chibis' flaw is that they themselves don't inhabit the host physically; when manipulating an organism, chibi' bodies are left completely vulnerable, and their destruction will free the host. This flaw is mended by their small size, which allows them to hide easily.
They are extremely effective, capable of possessing the famously-independent Medaka Kurokami or the President of the United States.
Chibi are capable of defending themselves well against typical mortals using their razor-sharp teeth, which only sprout when in danger. However, beings such as the Aura Energy Guardians can dispatch them easily, whereas divine figures are capable of causing them to explode from a distance.