Gantz
After being struck and killed by a subway train while saving a homeless man, high school students Kei Kurono and Masaru Kato awaken in a bizarre Tokyo apartment. There, they encounter a mysterious black sphere known as "Gantz," which forces them and other recently deceased individuals into a brutal, high-stakes game of hunting down and eliminating deadly aliens hidden on Earth. Armed with futuristic suits and weaponry, they must survive the ruthless missions to earn points and win back their freedom.