Many reviews here are nearly a year old, and the series is finally translated enough to see much much more development.
While it says one guy, there are actually three. Interestingly enough, they begin to follow all three rather than the main character alone. While most people complain about the "weak" main character, his is interesting in the fact that he is capable of sticking to his morals, regardless of the situation. He does realize he is being used in a political power struggle in addition to the other problems, and the so called "virus" is considerable more than it seems.
The series uniquely visit
the three males, all three of which reach different behaviors.
** Some spoilers **
The one male who decided to just indulge in several women a day began to find it boring, and is slowly going down a more sadistic route to sate his pleasure, in addition to pursuing the MC's sister, who refused him, so he wants her just because he not allowed to have her. The other male was utterly bullied, both physically and mentally, and is now taking revenge on the girls that are still alive that bullied him by, get this, NOT having sex with them (women who are pregnant become extremely wealthy and successful) , but having them around to see him in a position of power. While he hasn't gone as far off the deep end as the other male, he also realizes he is being manipulated, and the world is far more than it seems.
The MC meanwhile is searching for his lost love ** MAJOR SPOILER ** who is one of the main leaders of a rebel movement against the current world order that the MC suspects created the virus and killed anyone who got close to a cure.
Anywho, I really look forward to seeing this series develop more, it has certainly gone far beyond the harem trope I thought it would be.