>>127351712Fuminori gets into a nearly-fatal car accident that kills both his parents. In order to save his life, doctors try out an experimental type of brain-surgery that is able to save him. When he wakes up in the hospitable, everything is normal, but upon opening his eyes, he sees that everything is covered in flesh, cartilage, organs and blood and people appear as disgusting, grub-like monsters. He nearly has a panic-attack, but as he's a medical student, he's able to understand what's wrong with him and deduces he has some kind of agnosia that causes his senses to become distorted. Over time, it slowly develops so that his other senses match his sight, by making things smell awful, taste disgusting, feel real, and hear terrifying. His senses are opposites however, as things that are disgusting like corpses look nice to him, and he finds human flesh to be delectable.
When Saya "blossoms" by analyzing enough human DNA from Fuminori's sperm, and practicing her abilities, she spreads a pollen out that rides on air-currents and attacks humans to bio-genetically change their structure to become her race, dubbed Sayathians. This is how her race reproduces.
The best guess for Fuminori's fate is that he is also evolved into a Sayathian, but his mind and sight stay the same, so that all the terrifying and other-worldly changes the Earth experiences when Saya blossoms look beautiful to him, and he can not distinguish Sayathians as being terrifying.
