A Dark Sci-Fi Classic: ABARA by Tsutomu Nihei
When it comes to dystopian settings, hardcore sci-fi, and creepy skeletons/alien creatures, Manga artist Tsutomu Nihei might be the king. From BLAME! to BIOMEGA and a handful of one-shot mangas, his works are so sci-fi yet so real, you can feel the eeriness as if you were there in the manga.
One of his hardest, darkest works to this day is ABARA ["ribs" in Japanese]. ABARA was serialized in Ultra Jump from May 2005 to March 2006 and became a short 2-volume Tankōbon series. The series takes place in the future, where the earth is semi-destroyed and humanity is forced into cities connected by a single highway and multiple tubes. Humans within these cities begin mutating into "White Gaunas", creatures who can form bone armor and weapons [hence the name ABARA].
In an attempt to fight the threat of White Gaunas, scientists from the past who foresaw the future had created time machines to both send humans to a safe future & ensure the survival of the human race, as well as send off the White Gaunas to another dimension. However, this attempt did not succeed at wiping out the White Gauna mutation.
Many years later, White Gaunas had been studied by scientists, and eventually, Black Gaunas were created. Black Gaunas were human-White Gauna hybrids, possessing the abilities and strengths of White Gaunas yet still having their human minds. Denji, the story's main character, and Nayuta are two human test subjects, who eventually become Black Gaunas. Denji, being in between a human and a Gauna, goes on to face many crazy and dangerous situations.
The ABARA story is one mystery after another. The dark sci-fi classic has inspired many other manga artists, as many of Tsutomu Nihei's works have. Most notably, Tatsuki Fujimoto of Chainsaw Man has noted ABARA as a big inspiration, and even said he aims for Chainsaw Man to be an "Evil FLCL, and a pop ABARA".
Take a look through to check out images of ABARA throughout, and go give it a read; you'll be done before you know it.