Recommendations

Similarities
- big families (4 children - 1 oldest son and 3 daughters)
- conflicts of in-laws and marriage life
- mothers are frenemies
- fathers have rough and secret pasts
- ups and downs of marriages (featuring break-ups and reconciliation)
- both fathers I believe have chicken shops
- brother in-laws (established ones) are very cute
- clingy mother in-laws
- battles against miscarriages

Differences
Once Again focuses on love between parents and married couples, specifically married couples, and its ups and downs whereas My Father is Strange seems to focus on the love of parents and the lengths they go through. I also think that Once Again tackles thing quite heartedly and focuses on starting all over again (hence the title) where as My Father is Strange may seem light but in relation to its title, there is a bigger, and deeper plot from the everyday struggles of the family.

Personal opinion:
I personally found myself particularly interested in the third children's lives. Both families' chemistry are insanely amazing but there seems to be more sibling moments on My Father is Strange as I feel like Once Again focuses heavily on married life. Both dramas are very slice-of-life and comedic and I wasn't able to stop watching them once I started.

Have a lot of similarity, mainly in deceiving the bad guys. the difference is that Confidence Man is episodic while Shichinin no Hisho have a main storyline. Nana Ri no Hisho is also a more serious show,

It is similar in terms of the ML both series are physiatrist and FL is a subject of stalking by her ex boyfriend, just like in this series, the SML is stalking FL by being good. In Dinner Mate, FL and SML have both patient-doctor relationship, and ML is trying his best to solve the mystery around SML.

just the same
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just the same
accept they dont travel 8 times
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Another romance series with two boys in a lockdown/quarantine setting, but its more like "Like in the Movies" than "Gameboys."

Another romance series with two boys in a lockdown/quarantine setting. They go to the same school and must do a project for a class while being in lockdown at their respective homes.

Both these dramas take place in a college setting.

We get to see characters with their personnal struggles but also their daily college life and how they form friendships with the other characters of the drama.

In these dramas, we get to see people struggling financially, socially or emotionally.

The main difference is that Age of Youth is centered on a female cast who are roommates while ADSG's is centered on both men and women who are in the same department and meet in college.

Another romance series with two boys in a lockdown/quarantine setting. However, rather than being an online long-distance relationship, the two boys are living together.

It is part of the same universe with the same characters involved in the show. It also happens right after the events or at least it's suppose to happen right after. We won't know for sure until it is finally released.

Both about oriented career female lead working in the same workplace as the male lead who is her assistant.
The female lead can't accept the male lead who is younger due to society judgment of age difference between them.
Female lead has naughty mother and is always in conflict with her.

Both shows have the same female lead qin lan who is paired with a younger male lead with 10+ age difference.
The chemistry between both leads is so similar.
In the beginning the leads are co-workers and the romance ensues later on.

Both about a woman who lie about her age and pretend to be younger to be hired in the wanted workplace.
Dramas with older women/younger man and hidden identity of female leads as main plots.

At first one may think that the common ground with these family dramas are just that their stories are child-centered with Shin and Akiko doing the best for Kotaro and Miyuki respectively. If you like Akiko's personality, you probably would like also Kotaro's and vice versa. Both have comedy elements and gives off that warm feeling you often get with good jdramas.

In 3 Will be Free, Tay Tawan plays the son of a mafia boss, much like Gun in Golden Blood. Gun and Tay share a lot of characteristics, they both want OUT of the mafia business and want to just live their lives. Both get targeted by OTHER mafia bosses. In 3 Will Be Free and Golden Blood, both have a second Male lead who is the protective type (Joss in 3 Will be Free and Boat in Golden blood). Both have LGBTQ+ characters. 3 Will Be Free is definitely the Rated R version of Golden Blood.