Be careful! It contains spoilers

In both dramas:
(main similarities)
- FL hides her identity by pretending to be a boy
- ML quickly realizes FL is a girl (in AMA in 5 Episode, in MUG in 3 Episode). He helps her hide her secret without telling her he already knows she is a girl. He is her secret knight
- FL and ML go to university/academy together, they have to train hard to stay there. They also live together in the dorm as roomates
- It's from hate - to friendship - to love - kind of story
- ML is rich and well-known and incredibly handsome (my personal opinion)
- ML is very persistent to get FL. He doesn't care what other people will think about him being in a relationship with another "man" (it's even more impressive in AMA - the action of the drama takes place in the early of XX century in military academy)
- ML is cute, smart, cunning, cheeky, confident, but when he falls in love he would do anything for FL. His personality, however, doesn't change, even at the end - he is still adorable, he shows his love, but he doesn't become "a henpecked man" :)
- FL has a female friend whom she knew before the drama started
- FL and ML are friends. ML confesses/realizes his feelings first
- Besides ML another FL's male friend discovers her secret and falls in love with her (in AMA I would say it is even love triangle)
- ML has a female admirer, who wants to be with him
- ML quickly falls for FL but teases her a lot. He is jealous of other men
- There is a group of friends to which FL and ML belong
- ML's parent does not consent to his relationship (in MUG later his mother approves)
- Most characters find out about FL's identity at the end - in AMA in Episode 44, in MUG in Episode 23
- Similar shots/scenes appear: sit-ups scene, washing ML's stuff, dancing scene, rescue scene, winter scenery
- The chemistry between the main couple is great
- Besides main couple there are many other interesting characters
- FL and ML have their happy end :)

(main differences)
- AMA is much longer - 48 Episodes, MUG - 24 Episodes
- The topic in MUG is quite light. AMA is about the war (mostly second part), so it's heavier. In AMA there are some deaths, so I remember I cried a bit
- There are more kisses in MUG (mostly peck kisses but still), whereas in AMA you have to search it on youtube to see deleted scenes containing peck kisses
- In MUG there are lots of absurd accidents (typical for most cdramas)
- If you want to see MOSTLY cute romance - AMA is not for you, while MUG is perfect :)
- In AMA ML learns that FL is a woman because he sees her as a woman, in MUG due to accident
- In AMA ML helps FL a lot more than ML in MUG, he is her protector almost from the beginning, and she doesn't even know about some things he does for her
- In AMA FL and ML become a couple in (probably, it's not clear) Episode 41, in MUG in Episode 22. In AMA FL realizes her feelings really late, in MUG much earlier
- In AMA ML confesses his feelings in Episode 31, in MUG in Episode 20, but for us - viewers - it is clear MLs falls for FLs almost at the beginning
- In AMA FL finds out that ML knows about her identity in Episode 14, in MUG really late - bacause in Episode 20
- Genre: AMA is comedy/romance/action/historical drama (action takes place in the XX century), MUG - comedy/romance drama (action takes place nowadays)


Overall, I enjoyed both. However, MUG is more to watch for fun, for lazy Saturday and Sunday, while AMA is more, I would say, ambitious, demanding. It depends what you prefer to see :)


My scores:
AMA 9/10
MUG 8,5/10

Wow, that was long. I hope it'll be helpful for somebody :)