After finishing the whole series, I think one of the best things I can appreciate from this manga is the mangaka's ability to create three dimensional characters. The female protagonist may be at the top of her career, but she has her own vulnerabilities. The assumption people often make about power women is that they think and act like men and in the process forget their femininity. It's disappointing because it suggests that femininity hinders a woman's career, which is not true. If a woman's asset is her femininity she might as well use it instead of trying to hide it. The female protagonist encompasses all these qualities which gives us a three dimensional side to her character. She is clever, aggressive, independent, but vulnerable, scared and insecure at the same time, something that every woman today can relate to.
While the female protagonist is incredibly good at the job she does and is clearly a capable independent woman, she still finds herself bound by a lot of society's expectations of marriage, especially at the age of 35. I think this is certainly relatable to many women who are considered as 'old' and facing pressures of society to get married. We cannot criticise her for her insecurities in marriage, when half of the women today face the same problem.
To top it off, because of her past relationships, she has a lot of insecurity issues when it comes to the question of marriage. I can see some people think that she's docile and expected her to be this power woman type of lady. She does and does not fulfil that expectation at the same time. Yes, she's is independent and many men commented that she can do business like a man (yes that is offensive because it implies that women cannot do business, but we have to take into account that Japan and many other countries today are still very much a patriarchal society); but at the same time, as a woman, she finds it difficult to ratify her insecurities. Think about it, one of the things a lot of capable women have is that men find it hard to measure up to them and give them the happiness they wanted. They think that a woman's happiness is the typical housewife and kids ending, and women who excel at their work tend to intimidate men like them. It's sad, but often true and the manga certainly demonstrates this point very well.
That is also why pairing her up with a 50 year old man works so well. The male protagonist may be old, but as they say men are like wine, the older the better. And this manga clearly demonstrates this point. He is not insecure with his own capabilities since he has already well-established his career by this age and mature enough to give her the space she needed without completely letting her forget his interests in her. Of course one can argue that these qualities can also be found in a younger male, but the characters are decided by the mangaka, so who are we to argue? Besides, it is hard to find examples where a mangaka can turn the man's flaws into something that is loveable, but I find that this is the case for me in this manga. Princes are outdated anyway.