Recommendations

The only similarity is that both dramas are about corrupted schools and bullying and main leads trying to change that. Gakkou no Kaidan is a bit more idealistic I would say.

both has a teacher , who play the main character , and In charge of
the worst class in school ,and their relationship with their students more than just a teacher...

Both start with a one-night stand which leads to a pregnancy. The characters connect only after that event.

Dangerous "games" without escape, lead by a mysterious man/woman.

Gwanghae after becoming the king, the movie tells the story of king Gwanghae life, I hope that the drama will be able to reflect to the viewers the same personalitey of King Gwanghae during his tenure (as crown prince), no fear of success as long as Cha Seung Won plays the role of Gwanghae!

They have a similar theme and videos/photos as an important plot element...I would say more but it would be a spoiler, watch them both and you'll understand. ;)

Both have the main couple entering into a marriage against their will. The female lead in both agrees for family reasons
(to save her father's house in Full house while to save her family from loan sharks in Goong). Also, the male lead still loves his ex at the time in both.
What starts out as an unwilling relationship turns into love- with teasing, arguing, jealousy along the way.

Both ...

-have the same backdrops of WW II on Japan
-have Inoue Mao in the same role as a wife waiting for her husband comeback from battlefield
-are story-telling style drama/movie

because both drama consist of idols... im sure youll like it :) and youre beautiful is also fun like EXO next door both of theme is realistic

It is the sequel to Five Deadly Venoms. Originally Crippled Avengers is named The Return of the Five Deadly Venoms.
It's even better than the first.

It's also about receiving a heart transplant from someone and falling in love with their spouse/lover..

Kwak Sun Young gets into a car accident and develops this ability of detecting a man's past from his body odors. She divorces her husband when she finds out about his long history of girlfriends. Sun Young then sets up a business where she helps women and even the police track down suspicious men and husbands.

Both are comical + political satire romcom in the parliament and government.

Both are dealing with a student falling in love with an older guy. In both movies characters are mentally tortured because life isn't going easy with them, but thanks to their beloved they still manage to get through it.

Both are about girls who come from a humble background and then become royals. Both male leads are infatuated with another girl in the beginning of the drama.