"I want to thank everyone at HCMC FC," the South Korean said.
"The club has had two great seasons and overcame many challenges. I have done my best and will depart without any regrets."
Before departure he thanked all 30 players of the team for their contributions during the last two years.
The 62-year-old made his debut in Vietnam as technical director of Hoang Anh Gia Lai in 2018, and took over at HCMC FC in December the same year.
Last year he took the club to second place and was honored as the best manager in the V. League 1.
But this season the club only scored 28 points to finish fifth.
"Many people are disappointed with this year result. But personally I do not think so since the club is still in the top five. The Covid-19 outbreak caused a lot of difficulties, but everyone tried their best.
"I am also happy I have contributed to making Ho Chi Minh City the most professional club in Vietnam during my time here."
In late July the club made him step down as head coach and take over as technical director, and pursued Brazilian Ailton Silva. But since he failed to make it to Vietnam due to a second Covid-19 outbreak, the South Korean continued as coach.
In the league's second phase the team had four losses and two draws in nine games.
It is reported that the club is in talks with Silva, currently working in Thailand.
Meanwhile, SHB Da Nang recruited Brazilian midfielder Conceicao, who scored five goals for Becamex Binh Duong this season.
The 32-year-old is the second imported player at the ninth-placed club along with French forward Rafaelson Bezerra Fernandes.
It is reported that Becamex Binh Duong, ranked sixth, have renewed their contract with Burkina Faso midfielder Ali Rabo and are currently negotiating with French forward Youssouf Touré.
There is no information about who will complete clubs' roster of foreign players for next season, but options are limited since the Covid-19 outbreak prevents the clubs from getting people into the country.
The 2020 V. League 1 wrapped up last Sunday with Viettel FC winning their first ever title with a 1-0 victory against Saigon FC to end with 41 points.