time travel story but son can to save his mother

I have seen manny time travel drama where main lead comes to save female lead but in drama son comes to save/change his mother furure. the drama is well written for me this drama is the one of the best time travel drama in this year. i highly recommend any who haven't watched this drama or planning to watch. i even like the ost, the ost lyrics and the last episode scene matches perfectly.

As in the summary of the movie this not a typical happy ever after movie

The best scene of this movie which i like is the scene where they were together watching the fireworks. the boy promised that he will always stay with her ( which he can't fulfill because later he will find out the reason) then they kiss but the girl wish that she didn't want to forget the moments. when i watch this scene first times i thought maybe they will have happy ending together later in the movie but i was wrong. so if you have watched this movie my question are you okay. Thank You for reading my review. ✌️