I.M

He also released "Fly With Me" and "Horizon" on February 20, 2018 and April 19, 2019 respectively, both with a music video. In 2019 he also recorded an audiobook of Oscar Wilde's The Happy Prince for NAVER. In June 2020, I.

M mentioned he was interested in releasing a solo album eventually. In January 2021, Starship announced that I. M would have his first official solo release at the end of February.

The album is deeply personal, and shows a side of him different to the one he shows when with MONSTA X. As its title hints, the songs evoke various kinds of duality, like, for example, the one between the illusion of happiness and trying to convince yourself you're fine when in reality you're in pain, and they explore intense feelings, both positive and negative. On August 8, Starship Entertainment released a statement announcing that all of the MONSTA X members, except I.

M, renewed their contracts. I. M decided to not renew his contract but he will continue to participate in the group's future plans.

On November 15, I. M signed an exclusive contract with Sony Music Entertainment Korea. On April 19, I.

M launched a new YouTube channel hinting at an upcoming solo return. Sony Music, also announced that they would be launching a new official website on May 16. On May 16, it was announced that he will be releasing a new EP titled Overdrive on June 23.

On January 12, 2024, I. M announced that he will release a digital single on January 23. On January 15, the title was revealed to be "Slowly".

On March 12, it was reported that I. M will be making a comeback in April. The next day, it was announced that he will be releasing his second EP Off The Beat on April 3.

On March 21, 2025, I. M announced the digital single "Don't Speak", scheduled for March 28. On September 15, 2025, it was announced that his exclusive contract with Sony Music Entertainment Korea have ended and both sides have mutually decided to part ways.

As a result, his social media accounts were changed and transferred to I. M.