18 Again

Both are second chance romance stories where a divorced couple learns to see each other in a new light and begins to heal old wounds.

The male lead (28 years old) goes back to his younger body (18 years old) out of nowhere to find why the girl he liked commited suicide.
SIMILARITIES: Age, Younger Body

The two stories are very different, but they also have points in common: the male protagonist is torn between a love for basketball and a love for family.

18 Again and Reply 1997 share similarities in that they both explore youth and nostalgia through touching stories that blend humor, emotion, and innocent romance. Both series emphasize the importance of family and friendship, while also teaching lessons about self-discovery and the value of the present through looking back at the past.

- both have hidden identity
- great main couple
- similar comedy and both great at sentimental moments
- very good looking cast
- best friends that know about their condition

Both:
Deliver in-depth messages relating to life, marriage, relationships (similar themes)
Focus on being true to their emotions
Focus on character development
Involve different relationships

- warm family vibes;
- touching moments almost in every episode;
- good-looking MLs;
- hard-working MLs

Older male lead becomes young
Tries to develop a relationship with his son (and his daughter in 18 Again)
The difference is that the romance is between his wife in 18 Again whilst Mr Back is with an employee at his company

Both the leads reconnect with the people relevant to his life, in his two different stages in life. Both dramas have a slice-of-life vibe to it.

- FL becomes a teenager after being an adult
- Her brain goes to her teenage years not her body
- FL's relationship gets rekindled
- A story about regrets

Yoon Sang-hyun and Ryeoun were playing as father and son in 18 Again, this drama serves as their reunion.

Yoon Sang-hyun's characters in both dramas have anger issues and communication issues toward their own wives to the point their marriages are crumbling.

Both of Yoon Sang-hyun's onscreen sons in Namib (Shim Jinwoo) and 18 Again (Hong Siwoo - coincidentally was Ryeoun's character) has a lot of similarities like grew into timid boys with lack of confidence, seeing their parents fought every day, being bullied at school until other guys (Hong Daeyoung - whose older version was portrayed by Yoon Sang-hyun but the one who protected was Lee Do-hyun, the younger version but under name of Go Woo-young ; Yoo Jinwoo - portrayed by Ryeoun) protects them from their own bullies.

Namib, Twinkling Watermelon and 18 Again shows Ryeoun's strong bromance chemistry with his fellow male actors

Both couples have similar misunderstandings due to having married young and “wasted their youth” for/on each other. Both couples realize they still love each other and only resolve misunderstandings (and understand each other) after they part. No serious second lead love triangles. The supporting cast and friends are funny.

The similar points between shows are highliting the married life of female and male leads couple.
Female leads who were a devoted wife but unlucky in their married life.
Female leads who gave up their career in order to raise their childs and being a loyal housewife.
Second chance who let the female leads to practice their preferred career (journalist/doctor) after struggling with male leads.
Female lead who met in their journeys the second male leads who seem interested in their characters.

Both series have relationship troubles and time travel. Oops! Has a recurring day, but otherwise the same theme is followed

Both dramas are fundamentally propelled by a main character who must navigate a normal high school environment while desperately hiding a mind-blowing, impossible secret from everyone around them