Rina Aiuchi (?? ??, Aiuchi Rina, born 31 July 1980) is a female Japanese pop singer, songwriter and businesswoman also known under her original name of Rikako Kakiuchi or more recently R.
Born in Higashiosaka, Japan, she won the first season of the audition Super Starlight Contest, winning a recording contract with Giza Studio.
Her eurobeat-sounding debut album, Be Happy (2001) was certified gold in Japan and spawned a top-five song, "Koi wa Thrill, Shock, Suspense", which served as the theme song to the Japanese anime television series Case Closed and became viral hit.
Aiuchi's second album Power of Words became her best-selling album, selling over 419,000 copies nationwide and certificated platinum in Japan.In 2010, Aiuchi announced her retirement from the music industry and founded a dog clothing brand Bon Bon Copine in September 2012.
She later resumed her musical activities, appearing on several television shows in 2015 and releasing a comeback single "Warm Prayer" in 2018 under the name of R.