[23] Following his gold medal win at the 2025 Asian Winter Games, Cha was granted exemption from needing to perform compulsory military service in the Republic of Korea Armed Forces as is typically required of all able-bodied South Korean men aged eighteen to thirty-five.

"[5] His first coach was former South Korean Olympic competitor Shin Hea-sook,[9] and his skating idols were Evgeni Plushenko and Daisuke Takahashi.

In the 2012–13 season, he took the novice gold medal at the Asian Trophy and repeated as the junior champion at the South Korean Championships.

[30] In February, he represented South Korea at the 2016 Winter Youth Olympics in Lillehammer, Norway, placing fourth in the short program, fifth in the free skating, and fifth overall.

[28] Cha had to overcome injuries and boot problems to win his second national title in January 2018 at the South Korean Championships.

[35] Cha began his season by winning the silver medal at the 2018 Autumn Classic, after placing second in the short program with 90.56 points and first in the free skate with 169.22, ahead of training mate Yuzuru Hanyu.

These two bronze medals qualified him for the 2018 Grand Prix Final, making him the first South Korean man to do so and the first from his country since Kim.

[42] At his first Grand Prix assignment, 2019 Skate America, Cha doubled his planned quad in the short program placing seventh.

[47] Cha was assigned to represent South Korea at 2020 World Championships but the competition was cancelled due to coronavirus pandemic.

[28] His first Grand Prix assignment was initially the 2021 Cup of China, but following its cancellation he was reassigned to the 2021 Gran Premio d'Italia in Turin.

"[61] Competing at the 2022 Winter Olympics in the men's event, Cha skated a clean short program to place fourth in that segment with a new personal best of 99.51.

"[62] Cha opened his free skate with a hard fall on the quad toe loop but recovered to execute the rest of the program, placing seventh in that segment and finishing fifth overall.

He and choreographer Shae-Lynn Bourne chose the music of Michael Jackson for the short program while the free skate used the soundtrack of the James Bond film No Time to Die, which he cited as one of his favorites.

Cha opted to begin the season with back-to-back events on the Challenger series, citing a desire for "motivation for myself to improve as quickly as possible."

[67][68] After winning a seventh consecutive national title, Cha competed at the 2023 Four Continents Championships and finished fifth in the short program after falling on his jump combination and having his triple Axel called on the quarter.

[75] A month later, Cha participated in the 2023 World Team Trophy, for which South Korea had qualified for the first time in the history of the event.

Cha set a new personal best in the short program, coming second in the segment, and then won the free skate, helping the Korean team win the silver medal.

[80] Cha came sixth at the 2023 CS Nepela Memorial in his first competitive appearance of the season, before winning the silver medal at the Shanghai Trophy.

[28] He began the Grand Prix at the 2023 Skate Canada International, placing second in the short program despite a fall on his quad toe loop.

Despite continuing issues, he planned to participate in the Korean national ranking competition in order to maintain his eligibility for international assignments.

[83] He resumed training a week before the ranking competition, and with the use of painkillers was able to compete at and win the event, saying afterward that he would focus on recuperating the nerve injury to his ankle.

"[86] As he began the new season, Cha said he loves the lyrics of "Natural" for its strong voice and beat, and he chose it for his short program because it gives him "power" like "magic".

He withdrew from the competition before the free skate morning practice due to worsening ankle pain, as the injury he sustained during the previous season has not yet fully healed.

As there are many more international competitions ahead of him this season, Cha stated he would focus on treating his injury, which was aggravated further during the recent boot replacement process, before the upcoming annual Korean Ranking Competition, which determines the National Athlete Team membership while also serving as the selection process for the skaters who will participate in the Four Continents Championships for South Korea.

[93] One month later, he won his ninth consecutive national title at the 2025 South Korean Championships, solidifying his place on the 2025 World team.

[94] In mid-January, Cha competed at the Figure skating at the 2025 Winter World University Games in Turin, Italy, where he won the bronze medal.

One month later, Cha competed at the 2025 Asian Winter Games, where he won the gold medal ahead of three-time and reigning World silver medalist, Yuma Kagiyama.