When Aria the elf finds an adorable little kitten, she quickly grows to love it a bit more than might be healthy for her... mainly it's because her sweet little kitty isn't really a cat at all! No, the cute and cuddly creature that Aria calls Tama is actually a former knight reborn as a Behemoth, a legendary S-class monster that merely happens resembles a loveable domestic feline! Fortunately, Tama loves Aria as well and is more than happy to use his powers to defend the odd elf girl from dangers, real or otherwise, in BEHENEKO: The Elf-Girl's Cat is Secretly an S-Ranked Monster!