In 1975, Im played a high schooler in love with her teacher in Graduating School Girls, for which she won Best New Actress at the Grand Bell Awards.

In an era when Korean cinema was in a dark period resulting from severe censorship by an authoritarian government, this led to the emergence of the teenage demographic as a major consumer of pop culture.

[2] The "Really Really" series established Im as the most popular young actress of that period, and for the next several years, youth melodramas starring her dominated the theaters in quick succession, often with Lee Deok-hwa as her leading man: Prayer of a Girl (1976), Ever So Much Good!

She starred opposite Shin Seong-il in Love Song in a Peanut Shell, but it was poorly received, with audiences not prepared to see her break out of her "pure" image.

After a few years of forgettable television dramas, Im's career was revitalized by Kim Soo-hyun, one of the most famous TV writers in Korea.

As Im grew older, she remained active on television and the occasional film, in supporting roles as ajummas, aunts or mothers.