Both are a story of young first love b/w a kind good-hearted killer and an innocent rich daddy's girl.

The plot of an artist falling for a lone hit-man and entangled w/ the cop hunting him is closer to K-movie Daisy ....
BUT, the feel of the characters and especially the romance at the center, is very close to A Moment of Romance.

Also, in 1998 version, the Male lead has similar looks and style to Andy Lau .... the hair, the jacket , and the motorcycle.

- Both deal w/ young love and its growing pains.
- Both deal w/ the "re-education" of urban young people through hard labor in rural villages..... as part of the Chinese Cultural Revolution.

Similar subjects addressed differently ..... Under the Hawthorn Tree is a simple and elegant film of innocent love .... Balzac and the Little Chinese Seamstress is a film w/ a meaningful message, rebelling against the re-education.

--- Talk about "Screwball Comedy"!! ... Both are Hilarious.... w/ Outrageous characters ...and... even more Outrageous Shenanigans !!! ..... and ..... scenes that will literally have you Rolling-on-the-Floor w/ Laughter !!!
--- Both have leading men driven to do Crazy things out of Jealousy...
--- Both have a wonderful , lovable, adorable couple forced to live together due to Ridiculous circumstances.... then love grows , against-all-odds , and overcomes obstacles.

Differences:
--- Fated to Love You is strong on the Romance and love Triangle w/ family involvement .
--- Smile You is strong on the Family drama w/ a surprisingly Wonderful Romance to boot ... etc...etc...

Both Sageuks are/have:
--- a Strong Female Lead .... Smart, tough, brave, righteous and steadfast, etc...
--- an 'Epic Romance' ... most palpable Passionate / Intense Loves.
--- extremely Well-Crafted in ... directing, acting, cast, plot, costumes, music, etc....
--- Well-Balanced & Fast-Moving Plot ... ... interweaving of romance/revenge/action/intrigue.
--- Political Intrigue ... ... about ascension to the throne.
--- Unforgettable Characters! .... ... many, including the great villains!
--- Loves start w/ Mistaken Identities ... ... both females were in disguise when the male leads met them ...

Note: writing in Empress Ki, somewhat falters in 2nd half.