Kazuma Satou

Kazuma Sato (佐藤 和真, Satō Kazuma) is one of the main characters of Isekai Quartet. He is an adventurer from the KonoSuba universe. He is the brought to the KonoSuba universe following his death, making him the isekai character.

Plot
When the groups are split up, he is placed with Tanya and Demiurge.

Subaru Natsuki
He declares Subaru his rival, due to the fact that, while their circumstances are similar, Sabaru has the cushier life style. Unaware of the hardships Subaru had to go through to get that lifestyle, like dying several times.

Trivia

 * It is revealed by Kris that if he dies in this world, she can't revive him.