Kassy debuted as a solo artist on August 25, 2015 with her first single titled “In My Bed,” also known as “Chimdae Wieseo.”.
- Role Model: yoon Mi Rae.
- B.O. – Close your eyes (2018)
- Woo Jin Young – 어느 별에서 왔니 (2018).
- Giant Pink – I do not love you (2018)
- Hwang Chi Yeul x Seulgi – Our Story (2017)
- Sanchez – Sunny Day Rainy Day (2016)
- B1A4, BTOB Kassy, Young Ji (KARA ), A-Jax, April & Oh My Girl – Fingertips Love (2016)
- 2Bic – Starry Night (2015)
Kassy Radio Programs
- Park So Hyun’s Love Game (SBS Power FM, 2021) (18.06.2021)
- KBS CoolFM ‘Kiss The Radio’ (30.07.2017)
Kassy TV Programs
- Unpretty Rapstar 3 (Mnet, 2016).
Kassy TV Drama’s
- One Sunny Day theme for Hometown Cha Cha Cha (2021)
- Nothing Left to Say theme for My Roommate is a Gumiho (2021)
- Waiting For Spring theme for Best Mistake 2 (2020)
- Love Me Like You Used To theme for Start-Up (2020)
- Pick Up Subject for Chocolate (2019)
- Same Memories theme for Let’s Eat 3 (2018)
- At Beginning of Love theme for Wok of Love (2018)
- The Day I Dream theme for The Bride of Habaek (2017)
- Good Morning theme for Fight For My Way (2017)
- Dizzy theme for Swag (2020)