Born in Kamisu, while in her second year of junior high school Jōnouchi made her singing debut participating in the 'All Japan Enka Championship', a music competition organized by Tokyo 12 Channel (now TV Tokyo) and CBS Sony.
[1] In 1985 she entered the popular idol group Onyanko Club, and in 1986 she made her solo record debut with the single Ajisai-bashi; the song topped the Oricon Singles Chart, the first song in the enka genre to achieve this result.
[1] After the group disbanded, she appeared in several television shows, started an acting career on stage, and hosted the radio program Jōnouchi sanae no hātofuru daiarī ("Sanae Jonouchi's Heartful Diary").
[1] In 1995, she married the television director and producer Tadahiro Kimura.
[2] On 23 October 2019, she released Sanae Uta, her first studio album in 32 years.