seunghan used to watch music programs with his older brother and that’s when he became interested in being an idol, so he searched for artists' youtube channels and admired the singers he saw on TV, and he naturally wanted to try it. he said that he had been interested in vocals and dancing even before joining SM, so he practiced alone

he got casted after taking the entrance exam for School of Performing Arts

at the time, he received business cards from several other entertainment companies. of all of them, he was strangely attracted to one company that didn't say which company it was, so he went home and asked for that company’s business card. seunghan said that he called the number listed and it was SM

he joined SM around january 2020. regarding the reason for choosing SM, he said that he did not have any worries because SM was the most familiar to him since he was young, and he liked how close the artists within the company were to each other

he was revealed as a member of SMROOKIES on july 2, 2022. SM introduced seunghan as a trainee with outstanding skills in both singing and dancing

on august 20, 2022, he stood in front of fans for the first time by going on stage with sungchan, shotaro, eunseok and shohei at SMTOWN LIVE 2022: SMCU EXPRESS held in suwon. he then went on stage at SMTOWN LIVE 2022: SMCU EXPRESS @ TOKYO held in tokyo for three days from august 27 to 29

he appeared in the reality show ‘Welcome to NCT Universe’, which aired from november 30, 2022 to february 1, 2023 he appeared via VCR with sungchan, shotaro, shohei and eunseok at SMTOWN LIVE 2022: SMCU PALACE, which was held online

on may 31, 2023 SM announced that seunghan would be graduating from SMROOKIES and debuting through SM 3.0: NEW IP 2023