Parent story as this is its special episode; so you have to watch that before this. Not all characters from that are here but some of the more important ones are.

Similarities:
-Same actor plays both MLs.
-Both ML’s suffer from a medical condition that affects their everyday lives and those around them.
-Both are stories of triumph over defeat and hope even in the most desperate times.
-Both FL’s fall for the ML and refuse to give up on them no matter what.

Similarities:
-Both FL’s spend a long time away framed for a miscarriage.
-Both FL’s are highly intelligent and resourceful.
-Both ML and FL have secrets and ways of supporting themselves and each other.
-Both shows have large families that have power hungry, dangerous people in them.

The main show this spin off comes from. It's great to see the actual actors interacting after a year apart.

It’s prequel that has pretty good cohesion to the sequel;
-Actors that play their characters fathers/Masters/ancestors.
-Music; One OST came in from blood of youth, and the others are very good.
-Story; Takes place 20 years before TBOY.
You can even tell who’s who but their younger selves.

Similarities:
-Both have Wuxia elements/wuxia related.
-Martial arts scenes are awesome.
-Fighting for Justice.

Similarities:
-Same ML actor; very intelligent.
-ML with a traumatic past trying to get to the bottom of many mysteries.
-Crime solving, forensic setting.
-Interesting cases

Season 1 of this show; though not a continuation, it’s still really great and a worthwhile watch.

This is a sequel to the original, so context is required in order to understand the main protagonist and his prodigal genius.

Similarities:
-Both have leads with a terminal illness.
-Both have leads going through struggles because of that and coming to terms with it.
-Both sets realize that only by being truly together with support can they live each day to the fullest, regardless how short that time is.
-Both are melodramas.

Similarities:
-Both have intelligent ML’s who try to solve mysteries.
-Both have medical manipulation and mind control games.
-Both have antagonist doctors pretending to help.
-Other than the people immediately around the mains, trusting others can bring more harm than good.

Similarities:
-Both are by the same director and most of the cast is the same.
-Both have wuxia and mystical elements.
-Very rich and elaborate costumes.