Alex

Korean thrillers.
Both about kidnappings.
Father of the child is/becomes the main focus.
[ SPOILER ] The kids end up dying in both.

Prison setting.
Female led/driven plots.
Female leads are innocent of the crimes that sent them to prison.

Both dark comedies.
Both focus on families facing work/business struggles.
Death and murder soon overtake the stories.

Both darker themed detective jdramas.
Male leads hold a secret while investigating.
Both have a supporting female character who takes an interest in male lead.

Both plots revolve around supernatural abilities.
Both star Kamiki Ryunosuke & Arimura Kasumi (minor roles in SPEC, leading roles in FE).

A hitman falls in love with a woman.
Helps her with her passion projects- art/music.
Wants to be better and leave line of work for her.
[ SPOILER ] Female lead dies in the end.

Noble/rich male lead thinks the woman he loves has died.
Years later he comes across a lowborn/poor girl who looks identical to her.
Female lead has lost her memories and does not know she truly is male lead's long lost love.

Cold and closed off guys who prefer to work alone are assigned a new cheery and excited partner.
They prefer to stay in the "basement" while their new employee does most of the work outside.

Female lead goes "undercover" into a family business, with the intent to seek revenge for a crime from the past that her family member was severely affected by.
Romance occurs between female lead and male lead (the son of the business).

Female lead goes "undercover" into the home she once lived in as a child, with the intent to seek revenge for a crime her mother was framed for.
Romance occurs between female lead and male lead (the son of the household).

Male leads disappear from female leads' life after briefly dating in high school.
Later, female leads have begun dating an old friend, when male leads suddenly reappear in their lives.
They soon learn the secret reasons behind their disappearances- WS ML has memory loss, S ML has hearing loss.

Romance plot set in dessert/bakery shoppes.
Leads start with a bickering dynamic.
Male lead falls for female lead first.
Additional love interests in the form of supporting characters.