This anime series is set 2045 and a virus has killed 99.9 percent of all men; the only survivors are those who placed in cryostasis before it struck. Five of these men in Japan appear to be immune to the disease. For humanity to survive these will be expected to mate with many women; for reasons of plot artificial insemination won't work. These survivors include Reito Mizuhara, who refuses to mate as he is saving himself for his sweetheart Elisa, who can't be located; this is permitted as he works to help in the search for a cure for the condition. We also follow Shota Doi; he was bullied at school before the virus struck but now he enjoying be the object of girls' desires; rarely denying their advances. As theories about the origins of the virus circulate tensions rise and the surviving men become targets of those wanting them for their societies.
It must be said; this series is fairly trashy and makes no attempt to hide it... the obvious censorship screams out 'buy the DVD/Blu-ray to see what's hidden'! The story is decent enough and the central idea provides a good excuse for unlikely characters to be the centres of harems. It is also one of the rare examples of a character taking full advantage of his harem... I think the only other one I've seen was the infamous 'School Days' and that had far less fan service. The animation and character designs are decent enough although the frequent censorship is often distracting and seems to hide more than is necessary to maintain decency. Things get a bit more interesting as the series gets near its end but the end itself feels rushed; as if the makers were suddenly told they were on the final episode when they thought they had two or three to go. Overall I certainly wouldn't call this a must see; it wasn't terrible but it is certainly trashier than it needed to be.
These comments are based on watching the series in Japanese with English subtitles.