Tada made her debut in 1977, when still a high school student, on Shueisha's "Deluxe Margaret" magazine. Tada's stories belong to the sh?jo genre of manga and feature love stories centred around young female characters and their love interests. The storylines include comedic moments and are characterised by essential and sharp drawings.Some of Tada's most popular works are Ai Shite Knight, Itazura na Kiss and Kimi no na wa Debora.

Ai Shite Knight portrays the Japanese rock music scene of the early 1980s. The anime series based on Ai Shite Knight was the first ever to feature original songs performed within the episodes. Another of Tada's works, Miihaa Paradise is also set in the rock 'n' roll world.

Itazura na Kiss (Mischievous Kiss) - begun in 1991 and never completed - was by far Tada's most successful work in Japan. It tells the love story between Kotoko and Naoki from high school until after their marriage. The series inspired also an illustrated art book and two novels written by Nori Harata and published in Shueisha's "Cobalt" series. In 1996 a live action Japanese TV series based on Itazura na Kiss was also produced, starring Aiko Sat? as Kotoko and Takashi Kashiwabara as Naoki. In 2005, the series was adapted into a Taiwanese drama under the name of It Started With a Kiss and in 2008 an anime was also released.

Kaoru Tada died in 1999 of a cerebral hemorrhage. While moving to a new residence, she hit her head on a marble table and fell into a coma. Three weeks later, she died. She was 38.