SPOILERS!
Duty after school is a very good kdrama, and i would definitely recommend it to people who love/like action genres. But, in my opinion, everything that happened in episode 10 (final episode) feels like it was just rushed and not planned through. I honestly didn't like how basically, half of the characters who were alive just flat out died in the last 30 minutes or so of the final episode. I would give it 5 stars for having good acting, a decent plot (except for the last episode..), etc., but after everyone who i adored or liked as a character died, i just didn't really understand why they would do that...