Lesson in Love

20 years ago, Kei, a 23 year-old highschool teacher, fell for a student, Hitoha, a beautiful girl, but lost her from a tragic car accident. He’s now a middle aged factory worker who has just quit the job to visit Klavan in Ukraine. There lies a beautiful railway called Tunnel Of Love, where people say you can meet with your deceased beloved one. A freight transport runs once a day and it is said that the train takes someone you wish to meet

both series deal with student-teacher relationships. the female lead is the older one, while the male lead plays the student. both guys have a rebellious streak, but eventually falls for the girl.

Similarities:

Older female lead, and younger male lead

Teacher (coach, and student

Chinese drama

Similarities:

Older female lead, and younger male lead

Teacher (piano professor?), and student/pupil

Differences:

Korean drama
Piano theme

Both FLs are ML's somewhat older teacher who he falls in love with long before she reciprocates his feelings.

Both FLs are the older teachers of the MLs who start out rebellious but quickly fall head over heels for the FL and start chasing her.

In both dramas, the protagonists think they are half brothers and one of them interrupts their story.