Sagara herself had had doubts about whether this song would actually be a good start for her. In a 2006 interview for an NHK-BS documentary special on kayo kyoku, she remarked "At the beginning, I thought that this lullaby-like song wouldn't sell at all." Actually, it sold at least 1.2 million records, which would signify a mega-hit in Japan. On top of that, it won Sagara the Newcomer's Prize in the Japan Record Awards for that year. The Oricon rankings had not existed in 1967 but when it came into being the following year, "Sekai wa Futari no Tame ni" was ranked at No. 41 on the yearly singles of 1968. Finally, the singer would also make her debut appearance on the Kohaku Utagassen on New Year's Eve of 1967, a little over 7 months after her singing debut, something that was the talk of the town at the time.
For a little over a decade, Sagara would become a familiar face on TV as well as a familiar voice in her records. She was a TV personality and an actress, and even co-hosted the Kohaku 5 times out of her total of 13 appearances on the annual special. However, a scandal involving a tryst between her and another tarento in 1980 led to her virtually disappearing from TV, although she continued to release singles until 1983. A couple of years ago, she did release a new song titled "Inochi no Kokage" (いのちの木陰....The Shade of the Tree), her 48th single.