The plot is the same.
First male-female lead have a problem with love because of painful past love. The male lead's ex-gf left him without any explanation. The female lead's ex-bf left her because of his affair.
The female lead has problem with her name and want to change it to, accidentaly, a same name like the male lead's ex-gf. The male lead has miserable memory because someone that he respected the most (in this drama his hyung) died - and in his perception - because of him.
Then the conflict begin. the exes from both side return and pick on the leads' present moment. The male lead become indecisive between her ex and currently gf. The changing-name problem and so on..
The side story too. There is a story about female lead's eonni that has crushed with female lead's chef chief at work (female lead is pâtissier in the male lead's restaurant).
But I like My Name is Kim Sam Soon much..much..much more than AMO. Besides I watch this drama with this kind of plot first before AMO, it gives a good, healthy, hillarious, entertaining, witty comedy scenes and better story development for me.