Recommendations

Both dramas are Noona Romance set against the backdrop Korea's Hagwon culture.
Both provide a glimpse of the competitive nature, high pressure, business side of academics.

In both series, he saves the life of one of the characters by time travel.
They have crime, romance and humor.
The character has to go back in time several times.
It takes place in modern times.
A handsome man and a cheerful, lovely girl.

Si Jin similar to The Rise of Ning because of the plot, re-birth, incarnation. Female lead re-birth into a family

Both movies left a lasting impact on me. I experienced an equal measure of joy and sorrow from both. Nevertheless, I am happy that I watched them both.

Similar concept, same thing, both dramas involves Korean culture of academies for student that have them prepare for universities after school. Both series have internal teachers, fighting for positions, new challenges along with other rival academies and preparing lectures, classes, concept for studens.

Scarlet Heart Thailand is adapted from the same novel: Bubu Jingxin (Startling by Each Step) by Tong Hua

they are from the same universe, Novoland, and about the adventure of one young man who seek for justice of human being.

both have the same vibes

I think both share the same theme of camaraderie/brotherhood/friendship. The classic "the real treasure was the friends we made along the way" shounen trope fits these two dramas. TBOY is more serious and dramatic (but there's still humour at times), whereas IAM is fully packed with comedy. I think IAM is a wuxia as well, so that's another similarity. There are a lot of powers, techniques, and sects in TBOY, just like IAM.

The main character in IAM is the descendant & inheritor of one of the most powerful man in the universe so we can infer that he has the potential to be the The Very Best™, though arguably not as OP as TBOY main character.

Both are Thai BLs that involve first one and then both of the MLs time traveling into the past and changing events in their lives. At some point in both dramas, one of the MLs is hospitalized and the other ML travels to the past to try to convince him not to meet/become involved with him, in the hopes of saving his life.

Moon Gang Tae is a community health worker at a psychiatric ward who was blessed with everything including a great body, smarts, ability to sympathize with others, patience, ability to react quickly, stamina, and more. Meanwhile, Ko Moon Young is a popular writer of children’s literature who, due to suffering from an antisocial personality disorder, seems extremely selfish, arrogant, and rude. Moon Gang Tae denies love and Ko Moon Young doesn’t know it. The two defy fate and fall in love, finding their souls and identities in the process.

US is by the same author and in the same shared universe as blank the series. ……………………………………… …………………………………… ……………………………………….…. ………………………………………………….

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

There're similar because we got to see rejection of doctors' feelings.
It's fantastic to see how every one reacts.
Super recommended.

The angst of feeling like someone who is a "stand-in" and is just a replacement was prominent in both the shows