Recommendations

If u like republic spy drama or spy dramas in general then both drama are worthy watches. A cleaver protagonist and powerful antagonists with twists and turns.

More mature storytelling & line. Intelligent females handcuffed by ruthless & fearless love who are able to break through and live life terms more to their favor.

An unexplainable phenomena finds college-going student, Li Shi Qing, trapped in a never-ending time loop where she is always stuck on a public service bus which is due to explode, bringing death & destruction to not only herself but to all on board.

Desperate to find a way to escape not only the time loop but her tragic fate, Shi Qing inadvertently drags fellow bus passenger Xiao He Yun into the time loop as well. Together they try to find a way to alter their fate by ensuring the bus arrives safely at its destination, but attempting to do so proves anything but easy.

Jiang Xiao Yuan finds herself struggling with her identity as she travels across parallel universes that never seem to intersect. In her original world, she is an invincible wealthy daughter, but in another place, she becomes an ordinary working girl who has absolutely nothing. Along the way, she meets the mysterious Qi Lian, and together, they search for the truth involving the mystery surrounding her. Stripped of wealth, family background, appearance, and education, Jiang Xiao Yuan sets herself on a journey to find pieces of her "real" identity.

Cultivation
Martial Arts

Tang San, the lead character in the "Soul Land" (Douluo Dalu) Series, was once an outcast among outer sect disciples for mastering the forbidden Tang Sect skills. After death, he was reborn as the son of Clear Sky Douluo Tang Hao and Blue Silver Empress Ah Yin, retaining his previous memories.

Male and female before even meeting in real life.. Liked each other... And once met... Came into relationship very very soon... And no breakup or unnecessary misunderstanding...
Male loves female only and female loves male only

Though both the dramas have parallel universe sci-fi shit, Train shows more of a thriller showcase than Derailment while the latter shows more romance.
Even the titles are interlinked.
In Derailment, we see the FL trying to find herself but in Train we see ML trying to find a serial killer. Train has a very subtle romance and isnt the main genre.
But both are very captivating.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.

Fifteen-year-old Sei Saotome is the type of person who tends to fail at the most crucial times. After nearly becoming a high school drop-out, she enrolls into a school that is overambitious for her. There she meets the bold and popular Taiyou Udagawa; and the dreamy and stars obsessed, Mizuki Ootaka. After being asked by Mizuki to join the two guys in the Astronomy Club, it turns out high school life isn't as bad as she had expected.