Both dramas are about a career woman in her 30s who ends up in a relationship with a young co-worker 10 years her junior.

Both titles focus on a romance between first cousins and how they navigate their feelings for each other.

Both series focus on a forbidden romance between family members. Mistu no Aji features a uncle and niece who have fallen in love while 90 Days of Love they are first cousins.

Both series focus a smart female character who hides her intelligence to protect and enable her to maneuver in the restrictive and dangerous role women had in historical china.

Both series are about an older woman who has dedicated herself to her job and has let her romantic life suffer as result. They also involve a younger man as the love interest.

Both dramas are about the female lead learning to love herself as she transforms herself because she believes she is ugly. The male lead loves her regardless of her appearance but because of who she is as a person.

Both series are historical. They have a strong focus on the customs and daily life of the noble families during the time period. The main female lead is also intelligent and headstrong.

Both series involve the main male lead mistaking and continuing to view the main female lead as a bad, money hungry, duplicitous woman who seduces men to get ahead. Slowly the main male lead sees the female lead for who she is after putting her through many hardships.

Both series involve a young, naive, and silly girl forced into a marriage with a serious, cold guy. She then has to learn to behave in a certain way as she is thrust into the public spotlight. In Goong, the guy is the crown prince while in Prime Minister and I he is the Prime Minister.

Both titles are about a woman who is in her early thirties worry about the direction her life needs to go. Marriage, career, and dead-end relationships are common themes and worries for the main women.

Both titles have the main character moving from the city to the countryside and coming into themselves. In Koko ni Aru Shiawase it is a man in his late twenties while in Amachan it is a teen aged girl.

Both movies are about two men who work in the same company falling in love. No Touching At All is much more serious while Same Difference has a comedic focus.