Tada made her debut in 1977, when still a high school student, on Shueisha's "Deluxe Margaret" magazine. Tada's stories belong to the shōjo 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 (イタズラなKiss Playful 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 Satō 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 with lead actors Joe Cheng and Ariel Lin, and in 2008 the anime adaptation was also released. This series was also adapted into a Korean drama called Playful Kiss with lead actors Kim Hyun Joong and Jung So Min. In 2013 Japanese adaptation titled Itazura na Kiss: Love in TOKYO, starring Yuki Furukawa as Naoki Irie and Honoka Miki as Aihara Kotoko and has a sequal released in 2014, Itazura na Kiss: Love in OKINAWA, and Itzaura na Kiss2: Love in Tokyo which will show struggles of Kotoko and Naoki's marriage life. In 2015 the sereis was adapted into a Thai Drama called Kiss Me, Starring Mike D. Angelo as Thatrapee "Tenten" Warophat and Sucharat Manaying as Theraphat "Taliw" Ingkuranon. The latest one is a 2016 Taiwanese adaptation titled Miss in Kiss, Starring Esther Wu as Xiang Yue Qin and Dino Lee as Jiang Zhi Shu.
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 at the age of 38.
- Ai Shite Night, 愛してナイト, serialized in Margaret, 1981–83, 7 volumes
- Itazura na Kiss, イタズラなＫｉｓｓ, Margaret, 1991-, 23 volumes
- Itazura na Kiss Irasuto Shuu, 多田かおるイラスト集 イタズラなＫｉｓｓ, artbook published by Shueisha, 1 volume
- Kawaii Ojisama, Margaret, 1 volume
- Kimagure Enjeru, きまぐれエンジェル, Margaret, 1 volume
- Kimi no Na wa Debora (Your name is Deborah), 君の名はデボラ, Margaret, 1988, 2 volumes
- Debora ga Raibaru (Deborah's the Rival), デボラがライバル, Margaret, 1996–1998, 4 volumes
- Sabishigariya no Deborah, さびしがりやのデボラ, Margaret, 1 volume
- Horeru Yo! Koi, Margaret, 1 volume
- Ai Shi Koi Shi no Manon!, Margaret, 1 volume
- Kinta-kun ni Goyoujin!, Margaret, 1 volume
- Tiinzu Burabo, Margaret, 1 volume
- Miihaa Paradise, Margaret, 2 volumes
- High School Magic, Margaret, 2 volumes