Kira is a character from the anime Vampire Holmes who primarily appears as a talking cat. Although the detective Holmes insists that Kira is a black cat, Kira visually appears to be white, with the only black coloration being on the bottoms of its feet. This discrepancy in coloration is a defining and recurring trait, with Kira itself also asserting its identity as a black cat despite its predominantly white fur.

Kira is a male of unknown age and is specifically identified as a demon cat or an妖猫 (yō neko), which is a supernatural creature from Japanese folklore. One of Kira's most notable abilities is the power of speech, allowing it to communicate directly with Holmes and others in human language. Its behavior is highly independent and unpredictable, as it has a habit of leaving without any warning and returning just as suddenly, with no one knowing what it does during its absences.

In terms of personality, Kira is often depicted as a mischievous presence who enjoys teasing and playing tricks on the detective and his assistant. The character serves a supporting role in the story, joining the main duo as part of the eccentric household, which also includes their demanding landlady. Kira is an old acquaintance or friend of Holmes, and their interactions suggest a history together, with their conversations sometimes hinting at aspects of the detective's past, such as a potential romantic involvement.

Kira does not undergo a significant character arc or development over the course of the series. The role is generally static, providing a source of cryptic commentary and supernatural oddity within the detective agency. Kira appears suddenly in the narrative without a detailed introduction and largely retains an air of mystery regarding its true nature and ultimate purpose. Its precise motivations are not clearly defined beyond its own inscrutable agenda and its occasional amusement at the expense of the human characters.