Ajin: Demi-Human Complete 1-6

WHAT KILLS YOU MAKES YOU STRONGER

For Kei, and at least forty-six others, immortality comes as the nastiest surprise ever. He’s a rare specimen who needs to be experimented on for life—a demi-human who must die a thousand deaths for the benefit of humanity…

While studying at the library with her best friend Yui, she finds an old book called The Universe of the Four Gods. Upon reading the book, the girls are transported to a land resembling ancient China. Immediately on their arrival, a pair of bandits attempts to abduct Yui! A mysterious young man with the kanji for "demon" on his forehead comes to their rescue, but now he wants to be paid for his act of heroism!