Onyanko Club
On 21 June 1985, she became the 19th member of Onyanko Club after auditioning on the TV program "Yūyake Nyan Nyan", and she appeared on the cover of their first album, "Kick Off". Shortly afterward, she and Mamiko Takai, also a member of Onyanko Club, formed the group Ushiroyubi Sasaregumi. About this time, she acquired the nickname "Yūyu". Yukiko Iwai performed the lead vocals for Onyanko Club's fifth single, "Osaki ni Shitsurei", released in July 1986. From that point, she became the main vocalist for the majority of their albums, and was considered central to the success of the group.