"Jinrui wa Suitaishimashita" (Humanity has Declined) by Tanaka Romeo. Volume 9 is the final volume, where we find out why humanity has declined... or not. There were conclusive developments for some of the characters and events, but the great questions related to humanity are still mostly left to the reader's imagination.
Because the events related to the main character were portrayed in vivid detail, it's easy to miss some subtle background themes. Looking back, there were really many topics of great importance, including manned flight, space exploration, digital technology, spread of culture and subculture, and so on and so forth. For the final volume, the grand theme was the tale of the rise and decline of humanity, through the train of history in first person view. Only here did I realize what was happening in all previous volumes -- it really had been living up to the pompous title about "humanity" the whole time, but the scope of those large scale events may be too much for any single person to comprehend. Sometimes it's difficult to notice that history is being made.
Grandiose themes aside, it has been a pleasurable series to read. Some parts took a bit more focus to follow (especially the time paradox bits of volume 2), but mostly it flowed smoothly and were easily digestible. The main characters were few, but they all had very fresh personalties, particularly the cynical main heroine "M" (full name was never revealed). All episodes were interesting and memorable, though the game world from volume 5 were especially a highlight for me. Also, the proper use of the word "cracker" instead of "hacker" in volume 9, and many other bits that appeal to technical people that did not rely on technical jargons. All this with numerous detailed illustrations as a bonus.
Overall, a great series on many levels, definitely worth reading. Maybe reading it through multiple times will give us hints on the future of humanity.
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