3. The One and Only - I see that everyone recommended unusual couples, so I guess this counts too.
I think that the fact that the leads met in their childhood is a cliche, but at the same time I think that's the only one

 ani:

i thought the 2ML was the secretary

i mean yes the 2ML is the secretary since there's a secondary couple but i think the poster meant 2ML as in the second potential love interest the FL has (which in this case is her long-time crush). the secretary was never an option for a love triangle if that makes sense... but that's only my personal understanding of the prompt cause, in most dramas with a secondary couple, the 2ML has no romantic interest for the FL thus they are usually not close

4. saiai

5. nodame cantabile

6. The K2 - I don't recall there being many cliches in it, maybe because it's more action/thriller/romance...

 I AM SHOOKETH:

That Don't

Sorry my bad, Didn't notice 

10 dramas/movies where a ML (any ML) works as a secretary or personal assistant.

1. The rational life

2.Angel's Last Mission: Love

3. Business Proposal - if 2ML counts 

Yes, SML counts, that is why I said any ML, but they do have to be marked as a lead role, not a support role.

 emi:

i mean yes the 2ML is the secretary since there's a secondary couple but i think the poster meant 2ML as in the second potential love interest the FL has (which in this case is her long-time crush). the secretary was never an option for a love triangle if that makes sense... but that's only my personal understanding of the prompt cause, in most dramas with a secondary couple, the 2ML has no romantic interest for the FL thus they are usually not close

ah okay thanks, ill change my entry  :)

4. Cinderella and the Four Knights - Lee Yoon Sung is Chairman's General Secretary and is listed as main role.

5. Blade Man - Go Ja Kyung

6. My Girl (2020) - Jiang Jiang

7. Ugly Beauty (2021) - Ji Chen Mo

8. Yuttakarn Prab Nang Marn 

9. Across the Ocean to See You

+ does the ML from Hotel del Luna count?  he was pretty much handling everything  in the hotel