Kira is a serial killer, characterized as highly egocentric and psychopathic, with a few obsessive-compulsive tendencies. He is also a hand fetishist.

Kira longs for a peaceful and quiet life, safe from any worry, and does not wish for it to be interrupted. Whenever that life seems assured, Kira adopts a jolly and confident demeanor.[7][8] Although he is highly intelligent and possesses many talents, this yearning shows in his dislike of coming in first, and Jotaro theorizes from his many trophies that he even made it a point to never rank better than 3rd in any competition so as not to stand out.[9] Since his youth, Kira has been avoiding standing out, living a healthy life and following a strict regimen.[10] He becomes bothered when someone disrupts his habits and goes to extreme lengths to get them back. As his father pointed out, this will to stay in the background was so bad that if bullied or denied his favorite toy, Kira would bite his nails until they bled, being the only way he's found to express his frustration