O Amor Dura Para Sempre (2020)

* Cutesy naive female lead and cold but secretly sweet male lead
* Female lead has been in love with the male lead for years and idolises him. Male lead isn't interested (at first) and rejects her
* Light comedy with some heartfelt themes
* Male lead realises his feelings for female lead early in the show, but it takes a long time for him to admit it
* Domestic / living together
* Very sweet moments
* Cute and satisfying ending

I think the fact that they're both about the girl having a one-sided, long running love for the guy and the fact that they are primarily set when the characters are adults and working in hospitals definitely makes "Koi Tsuzu" have "They Kiss Again" vibes. Certain similar plot points which I won't reveal because *spoilers*

not really but I like both dramas.
Hidden Love is about a girl who falls for her brother's friend since she was child and never waver from her crush all the way into her adulthood. some parts were boring but still liked it. Actress is not my fav so I'm a bit tough on the drama but I still recommend it

Koi wa Tsuzuku yo doko made mo is about a girl who falls for a man she meets on the streets by helping save someone, and she vows to find him and profess her love to him so she becomes a nurse so she can get close to him,
the rest you gotta watch

It has same story line a high school girl chases a very handsome guy of same school. At first guy ignores her but when girl appears frequently in front of him then he starts to notice her and somehow they end up living in same house and finally fell in love for her.

Similar setting, FL is madly in love with ML and chases after him... ...........................................................................................................................

They have a similar vibe. Mostly sweet and low on angst. Perfect cold man and sweet and naïve female lead.

similarities:
- They are a couple (secretly) very early and work in the same place.
- The ML has a scary reputation at his workplace as "the devil" but that doesn't take away from him the role of the hottest guy. (as hase who is known as the phantom)
- The FL is cheerful, motivated, helpful, funny, naive, kind .. and dedicated to her work.
- there's a slight age difference that is never mentioned, when she was in high school he was already a doctor.
- She comes from a modest background, and he comes from a wealthy family.
- A co-worker falls in love with the FL.
- it's adapted from a manga.
- It's a J-drama.

it's not the same atmosphere as Love is Phantom, the ML is not so gentle with the FL at least he wants to make himself look tough and cold in the beginning. But their romance gets cute. The FL is not as naive and has more personality than Momoko.

The lead actress is the same, both characters share similar personalities. She stumbles over herself often, she has a number of insecurities, daydreams way to often, and makes a good deal of blunders but her bounce back persistence makes a way where there doesn't seem to be one.

A main character is a doctor (FL vs. ML). FL first meets the ML years before when he helps her in a situation, and then doesn't forget him during the years apart until they meet again. Their reunion, however doesn't go as FL planned at first.

.Both FLs fall for the Male leads at first sight.
.Both FLs chase the MLs.
.Both MLs are not interested.
.Both MLs have lost their gfs before.
.Both FLs and MLs have a happy ending.

- Both Medical Drama
- Female lead like Male lead first
- Both ML comes from a rich family that owns the hospital
- Both shy FL
- Both selfless FL
- Both FL is still trying to find themselves
Note (chocolate has a more serious vibe)

A cold man meeting and reluctantly falling for a warm and quirky woman. And there is the thing with him calling her baka/idiot in both dramas - apparently in Japan it's a sign of a great romance...!

Nagao Kanji works for an advertising agency in his hometown of Ehime Prefecture. He is assigned to the Tokyo sales department where his colleague Akana Rika takes care of his work. One day, Kanji is invited to drinks by Mikami Kenichi, a former classmate from his hometown who is now in Tokyo, and he is also reunited with Sekiguchi Satomi who has feelings for him. However, Rika ends up joining them when she delivers Kanji’s wallet which he had left in office. On the way back, Rika tells him, “Kanchi, shall we kiss?” and he is rattled. There have been rumours in office that Rika is in a relationship with their boss Waga Natsuki.

ML is a doctor who appears cold at first but has a warm heart. Sweet romance between ML and FL. Characters met years before then reunite later.

While Doctor John is more serious, I think these two dramas have a similar tone. The romance is similar, and both are sweet and heartwarming dramas about the medical world.