Both are about childhood friends turned lovers
Dramas have feel-good vibes and the leads have great chemistry.
Soundtrack #1 shows an unrequited love that blossoms when the leads are adults, yet road home both leads fall in love with each other since their school days

Both dramas are about first love.
The leads are different, yet despite their differences, they fall in love.
They are separated by fate's order and are reconciled when they are adults.
The tones are somewhat different, as le coup the foudre is fluffy and warm, yet Road home is a bit of a melodrama. Both are very romantic and swoon-worthy

Both dramas are about first love in high school days.
The leads are separated due to some complications in their lives and are reunited years later as adults, yet they have many unresolved issues during their relationship.
The leads both have had a somewhat problematic adolescence that lead to their breakup eventually.
In both dramas, the leads reconcile as adults and still love each other.
Both are romantic and dramatic at the same time.

Both dramas are focused on First Love ( one in school and one in college).
The leads are quite different but fall in love anyways and are separated by fate's plan.
Both dramas show the leads with heavy baggage in their lives.
The lovers reconcile years later and still love each other.
Road home is focused more on the couple after reconciliation and is really romantic, Yet L&P has a darker tone and the leads take a while before they can reconcile fully.

The main leads in both dramas are supernatural creatures who have been humans in the past and have been leading a long life
They come across their lovers from the past life and in the mortal world, there are complications as always

The writer is the same in both dramas, giving off the same vibes. You can see so many similarities between the two.
The day of becoming you has a different story with fantasy elements( bodyswap), yet Hi venus is set in a medical setting.
The FL is the same in both dramas.
Both dramas are romantic and warm

Both dramas revolve around hospital/medical settings.
The leads start on the wrong foot, yet they soften over time.
Both have comedic elements and are warm

In Both dramas the leads are acquainted in the past( L&P leads are lovers in college but MLH the ML has an unrequited love since childhood)
My little happiness is sweet and fun, while lighter and princess is a little dark and thorough
The leads are reunited while they are older and become colleagues

Both dramas are about young lovers who are separated because of life mishaps but keep loving each other despite the separation
In both dramas the leads meet again when they are adults and reconcile
The leads in both have somewhat complicated and heavy pasts

Both dramas are set during school/college days
The leads have a love-hate relationship at first that turns into romance
The leads are separated due to mishaps showing up but keep loving each other and meet up again in the future
The characters in both have heavy baggages from their past and have been through trauma
The leads become colleagues too

Both dramas revolve around school and college days
The leads fall in love while at school
The leads are separated due to mishaps and are later reunited
Past love cannot be forgotten sort of dramas
Both give off warm vibes

typical body swap dramas
the leads are in a relationship and have to live with bodies switched
TDOBY the swap returns to its original body but in Kojinsa Arimasu the story is a bit different