Seung Hui finished 7th in the rookie standings in 2020 and 51st on the money list. She improved somewhat in 2021, finishing 45th on the money list with her first top three finish, a tie for 3rd at the KG EDaily Ladies Open. 2022 was much the same kind of result for her.

However, she broke through in a big way starting in 2023. That season, she had 8 top tens including her first runner up result. She earned 428 million won and finished 22nd on the money list.

As good as 2023 was, it was 2024 when she became a major star. She had 10 top tens that season, but more importantly broke through with her first two tour wins. The first was the biggest: despite being challenged by multiple huge stars, she won the Korea Women's Open, arguably the most important event on tour. She followed that up in October with a second win at the OK Financial OK Man Open. She ended up earning 925 million won for the year, by far the most she had ever earned in a single season, and finished 8th on the money list.

Ro started 2025 with an appearance at the Foxconn TLPGA Players Championship in Taiwan. She finished tied for 13th there.