Both are romcoms that start of with a hate-to-love plot and both deal with the pressure of dating under public scrutiny as celebrities.

Kokdu hasn't come out yet, but the synopsis sounds similar to DaYS.

- ML is a supernatural entity that deals with death
- ML meets FL through special circumstances
- ML would live a lonely existence if not for meeting the FL

These two shows gave me somewhat similar vibes:

?? Older FL/Younger ML
??Hard working FL lead
?? Supportive ML
??Cohabitation

Night Wanderer hasn't come out yet, but they appear to have similar time travel themes and an element of suspense

-Supernatural element
- Protective Male Lead with a good heart
- Female cursed to live long life
- Mysterious older female that guides main leads to each other

This drama has a very similar feel to Circle. They both feature scifi, suspense, mystery, with a bit of romance.