Rubber Soul debuted in 2015 as a joint project of record labels Universal Music, Happy Tribe Entertainment, and With HC.
This marked their official debut and the group continued promotions on various shows for a few months with both "Life" and their side-track "Lonely Friday" with features Mad Soul Child's Jinsil.
[6] The group performed alongside other Korean artists such as MYNAME, G-Friend, Galaxy Express, T-ARA, MAMAMOO and others in September for the Asian Music Network festival.
[7] In October, 2015, the group participated alongside Giriboy, Black Nut and Genius Nochang in a "1st Look" pictorial for Vans and the winter collection "Designed for the Elements".
[8] Kim participated in the reality show Unpretty Rapstar 2 as a contestant starting with episode 6.