One made his debut as a solo artist under YGE following single album One Day on July 11, 2017, with self-written and produced lead singles "Gettin' By" and "Heyahe. It was also reported that he became the first male solo artist to debut from the label in 14 years since Seven's debut in 2003, excluding Kang Seung-yoon who debuted as a solo artist in 2013 but later debuted in Winner. From July 15–21, a pop-up store for One titled "One Day One Week" Magazine Shop was unveiled, displaying his album, debut films and exclusive materials. On July 21, One held his first fansign for single album "One Day" at Luft Cafe.