Did not watch the previous School series, without any expectations surprisingly this series enjoyable to watch.

The pacing is nicely paced, main lead acting are good. The second main lead acting a bit off though.
The story is light and suitable for entertainment purpose, no need to think just watch and enjoy. The ending is not too great though, very flat and like just want to end the series quickly with happy ending.

A lot plot not so realistic, like how easy for Ho Sung to just accept that he is a father? Why nobody do DNA test to prove it? He was ghosted by the ex gf, if the ex gf really was pregnant with his baby why don't she tell him instead of ghosted him? And just dump the son when she want to study abroad, like she is not happy with Ho Sung currently move on and have a new gf and just want to ruin Ho Sung life.
When the school director office was robbed, how come there's no alarm? He have the key to the director room?
Ki Joon grandfather surgery went well, then how come he suddenly died?

Overall watching this series is enjoyable if you don't put any expectation and think too much.
Good acting from young actors and actress, especially the main lead ( Kim Yo Han and Cho Yi Hyun)