Satou Kazuma (佐藤さとう 和真かずま) (last name Satou, first name Kazuma) is the main protagonist of the KonoSuba series. He was reincarnated into the Fantasy World after dying.

He was originally a student from Japan who always skipped out on school in favor of lazing around at home playing video games. Eventually he died in an accident and was sent to the fantasy world alongside the Goddess of Water Aqua in order to defeat the Demon King, who sought to oppress the free peoples of the fantasy world.

Prior to his new life in the Fantasy World, Kazuma was a hikikomori, thus isolating himself from society and spending all his time in his room playing video games, all while maintaining little to no relationships outside. Some of these traits would manifest from time to time in the Fantasy World, such as becoming extremely nervous when first meeting the beautiful Darkness and resigning himself to lazing around under his kotatsu at all times.

After coming to the Fantasy World, Kazuma becomes much more social and outgoing and was initially excited at the prospect of becoming an adventurer. Despite this, however, Kazuma becomes increasingly pessimistic about his new life as he discovers the harsh reality of being an adventurer, such as the low pay and life-threatening work.