Daechi-dong Class 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

Kang Myeong-Mun went from being a prestigious high school teacher to a shabby private academy instructor due to his failure in the ‘exposure of private school corruption.’ On the days when he regretted his past, he was forced to regress to the time when he was a beginner teacher due to a certain incident.. With the foundation of college entrance exam know-how that he has been gathering until now, his struggle to become the best teacher begins!