Kaoru originates from the horror manga "Kichikujima," where he belongs to a mutant cannibal family possessing supernatural abilities and serves the deity Zanta Maria. He possesses distinctive physical traits, including abnormal height, missing teeth, and is frequently depicted wearing a mask. Within his family, Kaoru holds the position of eldest son; his siblings are Mari (eldest daughter), Anna and Kanna (twin sisters), and Satoru (youngest brother).

The spin-off anime "Kaoru no Taisetsu na Mono" reimagines the character within a comedic, slice-of-life setting. This adaptation features super-deformed versions of the characters, entirely removes the horror elements and supernatural backstory, and places Kaoru in ordinary, non-horror situations. While retaining physical attributes like his height and missing teeth, Kaoru functions purely as a wholly comedic figure in this iteration, disconnected from the original lore.

There exists no narrative continuity between the horror manga and the comedic anime. The anime consists of 50 one-minute episodes, each depicting standalone scenarios unrelated to the manga's plot or character development. No official media beyond the original manga and this specific spin-off anime features Kaoru.