Rookie Employee Kim Cheolsu is a Manga/Manhwa/Manhua in english language, Drama series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

On the day he was rejected by the company he had devoted his life to, He went back to the moment of his first day at work. Kim Cheol-su, a low-spec rookie employee who joined Han-young, a leading domestic company. Can he finally achieve his long-desired position as the ‘CEO’ in this lifetime?