Oota Yokan

Eric has had a hard life. At the age of 16, his village was overrun by monsters, who killed his friends and family. He soon became a soldier, but failed to save the life of the woman he loved. In the end, he died on the battlefield, surrounded by the bodies of those who he couldn’t protect.When Eric wakes up, he finds himself in a baby’s body. Realizing he has been reincarnated, he quickly wonders what is going on before he gets another shocker: the man and woman who are raising him are in fact his previous life’s parents!That’s right - Eric was reincarnated, but as himself. No alternate worlds, no skill trees, just his memories sent back to the moment he popped out of his mother. Armed with the knowledge of his past self, Eric vows to save everyone now that the universe has pushed the reset button for him.web novel

A remake of the webcomic "Hito Kui" by MITA-sensei. There is a rash of sudden group deaths, where all members die of a heart attack. These people receive a chain mail and are then drawn into the lair of a man-eating monster, a "Hitokui." Generally, only the last person standing survives, with the others dying of a heart attack in the real world when they are eaten by the monster. High school student Youta is drawn into one of these lairs, which doesn't go quite as the monster planned. He survives, and retains his memories of what happened there. However, it looks like the world of man-eating monsters is not finished with him yet…

Multiple instances of mysterious mass deaths are erupting all over the city. The only similarity between each mass death is the time in which the victims were found dead. Trainee doctor Sasaki finds himself in the midst of one of these mass death events. He must now fight his way out of a dungeon ruled by a man-eating monster: "Devourer." As other humans are slaughtered and eaten alive around him, will he be able to escape out of this dungeon and bring an end to these mass murders?