Kaoru Kobayashi (?? ?, Kobayashi Kaoru, November 30, 1968 – February 21, 2013) was a Japanese newspaper deliveryman who kidnapped, sexually assaulted and murdered 7-year-old Kaede Ariyama (?? ?, Ariyama Kaede) in Nara on November 17, 2004.
Kobayashi, an ex-convict and pedophile with a record as a prolific sex offender, was sentenced to death for the murder of Ariyama and was executed by hanging at Osaka Detention Center on February 21, 2013.
Ariyama's murder caused a surge in the moral panic against otaku culture in Japan.