The Peanuts Biography (Wikipedia)
The Peanuts (ザ・ピーナッツ Za Pīnattsu?) was a Japanese vocal group consisting of twin sisters Emi Itō (伊藤エミ, Itō Emi) and Yumi Itō (伊藤ユミ, Itō Yumi). They were born in Tokoname, Aichi, (Japan) on April 1, 1941. Soon after the twins' birth, the family moved to Nagoya.
The twins were discovered while performing at a club in Nagoya in 1958 by pop impresario Sho Watanabe. He brought them to Tokyo and gave them the name The Peanuts. They made their first recording “Kawaii Hana” (“Cute Flower”) in 1959. In their early years they sang Japanese covers of standards, foreign hits, and Japanese folk songs; then they began singing originals, written by their producer, Hiroshi Miyagawa, and such songwriters as Koichi Sugiyama and Rei Nakanishi. They are first performers of "Koi no Vacance".
Later, the twins embarked on a brief acting career, notably in the 1961 film Mothra and Ghidorah, the Three-Headed Monster. In the audio commentary for the DVD of Mothra vs. Godzilla, it is noted that director Ishiro Honda fondly recalled the Itos' professionalism. Though not primarily actresses by trade, they were surprisingly skilled, learned their lines quickly, and always worked on time, despite their own busy schedules.