Dive into You

Both dramas:

Centered on a Man in a Woman's bodyich creates a faux gay loveline beyween the leads:

In Comebacj Alive it's a faux GL
Dive into you will likely feature a BL or possibly both BL and GL as well as straught lovelines x2 once swapped back.

In both of these shows a brother and a sister accidentally soul-swap with each other.
One has romance while the other doesn't.

both are kdramas with a time travel aspect
living as high school students in the past with the aim of trying to prevent something
romance elements

Kdramas in which a female lead is transported back in time, ending up in a different body, and trying to save the life of a loved one who is dead in the present time

dramas in which the female lead travels back in time and uses this chance to save the life of a lost loved one
fantasy romance

kdramas with:
-different time lines , one where the characters are in high school and one where they are adults
- female lead is popular and known in present timeline
- one of the characters is a student athlete
- Bo Na playing one of the central characters
- romance and comedy

Dive into you features a body swap/time travel plot, while 21-25 is grounded in reality and follows the characters grow and develop over multiple years

romance, comedy dramas with actors who are/were kpop idols
fantasy elements that cause the female lead to end up in the body of a guy
hetero romance with some gay vibes due to the body switch

romcom kdramas in which two characters switch bodies and have to navigate a new situation
bromance elements
one of the leads is/was a popular actress

similar:
- FL travels back in time to save ML
- celebrity x non-celeb relationship
- highschool first love

different:
- FL has a bodyswap with her twin brother whilst trying to save ML (bromance)
- Role reversal: FL is a celebrity and ML is a bodyguard in Dive to You vs ML is an idol and FL is a fan in Lovely Runner