Recommendations

Both dramas are same genre (xianxia, romance, and fantasy).
Both dramas are also set in the same universe.
Both dramas have the same author.

The deep understanding of people's minds and life choices in a family setting. Father-son relationship, uncle-nephew relationship, husband-wife relationship, teacher-student relationship, and a deep connection with soulmate. It is written in a very subtle way that requires thorough thinking and the feeling of this drama will linger around the watcher for years in the same way as Lost You Forever does.

Both the Male leads from Mr. Bad and Night of love with you are fictional character.
Mr. Bad - Male lead is the Fictional character from the novel written by Female lead
Night of love with you - Both Male lead and Female lead are the fictional character from the Manga

Night of love with you (Synopsis)
An accident happens when manga character Qi Qi, who has played antagonist female supporting roles for many years, enters the new comic "Night of Love With You" and becomes the heroine Luo Qing. In a story where the male lead has suddenly disappeared, the supporting female lead is closing in and the male antagonist doesn't have a love story anymore, will Qi Qi find her happiness?

Both the Male leads from Mr. Bad and W-Two Worlds are fictional character.
Mr. Bad - Male lead is the Fictional character from the novel written by Female lead
W-Two Worlds - Male lead is the Fictional Character from the webtoon written by Female lead's Father

Mr. Bad (Synopsis)
Nan Xing is an online novel writer whose main character is based on her idol, Lu Zi Chen. The main antagonist is Xiao Wu Di, a cunning and manipulative martial artist.
One day, Nan Xing makes a wish for an "unforgettable love" in a Fairy pool. To her surprise, Xiao Wu Di, the villain of her story, suddenly appears before her! She tries to avoid him, but Xiao Wu Di finds her and threatens her into taking care of him. Unfortunately for him, Nan Xing's wish comes with a special power: whenever she needs help, Xiao Wu Di teleports next to her to fulfill her wish.

Both have genres of Thriller, Mystery and Drama.

Both have people envious of the FL, rivalry, classical music, cheating partners, darker atmosphere, rich and powerful people, secrets,

But one thing, The Penthouse is crazier!

Very similar concept the beaten-up bullied kid gets mistaken as some dangerous dude. He tries to keep it a secret and while also helping other bullied kids. Its funny and short. It you liked boyhood you might actually like this drama special even more.

The son of 18 Again's main character is the main character in Twinkling Watermelon. Both of Ryeoun's characters met his 18 years old father and create heartwarming friendship/bromance.

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…

Han Joon Oh is a leading South Korean celebrity. He is stunningly good-looking and tall but is secretly plagued by an inferiority complex that leaves him permanently insecure. One day, he is hired to appear in a public service video. But the shoot goes horribly wrong, and Han Joon Oh is involved in a potentially fatal car collision. He is only saved by the quick thinking of a female firefighter named Kang Young Hwa, who pulls off a heroic rescue.

Han Joon Oh’s representatives hire Kang Young Hwa to work as the star’s personal bodyguard, recognizing her incredible talents. But when Han Joon Oh awakes from his stupor in the hospital, he has changed completely – as his body has now been possessed by the spirit of a nobleman from ancient Korea. This nobleman, named Do Ha, was killed by his beloved wife Han Ri Ta – and the vengeful spirit is on a single-minded quest for retribution…