Recommendations

The battles inside the companies of both series seems a bit similar.
Both male protagonists grown up from sleezballs to a somewhat righteous and reliable fighters for the justice within (and even gather employers around them.)
Both female protagonist are neiher too whiney, nor crybabies. Both are strong, yet atractive.
In both series the romance between the both main leads is lacking if it's even there.

Both main protagonists are somewhat violent.

Dramas depicting the love lives and work-related affairs between a woman, which raised herself in her carrer, but it's also known for her savage and bursting temperament & a meek and a not-so succesful man. In both the men struggle a lot under the women's leadership, but gain not only a lot of proffesional knowledge, but also learn to see their vulnerabilities and save them from the judgement of outsiders. In the end both start to compliment each other.

Both depicts the strugling of the modern office workers and try to take a look at them. Both include un-even couples within the same company.
While MT&NJG depicts a modern grown woman in a somewhat traditional society; 3 generations men of the same family and a struggling dad, trying to raise his children..
RO depicts 3 youngsters fighting for a job for which they are not quite capable of, a mother trying to break the glass ceiling and raise herself as a manager. Both have a protagonist that tries to break his prejudice and mistrust of others about himself, but first starts crushing his/her prejudice about others. Both have changed a lot of jobs, before landing amd finding his/her place finally in this one. In both their partner has a calmer temper, but is not a complete push-over as it raises himself/herself into a fighter of some sort.

Main couples in both live neirby to one another and somewhat run to each other even outside work. They grow to like one another- as they start to understand better the problems of the other.

Both involve a man and a woman having the same profession. While the man is considerate "elite" in his, the woman is struggling heavilly both for recognition and with money.

The leading men in both shows are so confident in their abilities and worth that doesn't realise their unfairness to others as it mostly doesn't came with a bad feeling, but is with a rather sharp tongue and judgement. Both consider themself elites. Both are somewhat abusive towards the female lead. Female lead in both is being considerate by them below their level and is a crybaby with a lot of troubles.

Both are recent office dramas which involve a somewhat unbelievable situations for examples of the struggles of the employers of the companies and have comedic aspects.

Both are office dramas, starring Ha Suk Jin in which he plays a somewhat despicable man (he is a better human in RO), while the female worker is honest and desperate by default (more desperate in DS)..

Both involve a female office worker who thinks she has a terminal illness and therefor start changing her attitude from a meek to a much more fighting one.. which starts changing her life.

The newer Let Ratree is a remake, the basic plotline is the same while some things were changed.

Both have male protagonists that are famous prosecutors who end up in prison. Both have top notch acting, intricate stories about crime, power, jealousy and revenge. The cast is amazing in both dramas.

Both revolve around cases of men framed and wrongfully sentenced to prison for having killed their family members. Both have prosecutors protagonists trying to uncover the truth, fighting the rich and powerful chaebols behind the case.

Both have male protagonists that were framed for their family murders and were unjustly imprisoned. They both struggle to bring the truth to light.

Both have a male protagonist that is a convicted swindler who gets out on parole with the excuse of taking care of a family member. Both undergo significant changes, as tragic challenges await for them outside of prison.
One is a drama, the other a movie.

Both about a weird teacher coming to a school to teach with a different style than all the other norm teachers. HAMMER SESSION is about getting the students to an elite school while Taiyo to Umi no Kyoshitsu is about keeping your good mark to get to your 1st choice school. In both dramas, the students learn to trust the teachers and learn a lot of moral lessons along the way.

Both dramas include lawyers who solve a crime that is close to home. In Defendant the victims were his wife and daughter whilst in Whisper the assailant is his new bride and her lover (so he his less inclined at the beginning to solve it). In both dramas they have a female helping them solve the crime. Both have similar feeling to them as well.