Battle Game in 5 Seconds (出会って5秒でバトル, "5-Byō de batorugēmu") is a Japanese manga series written by Saizou Harawata and Illustrated by Kashiwa Miyako. It's published in Shogakukan's Ura Sunday and MangaONE since August 2015. It is a remake of Harawata's webcomic by the same name. An anime adaptation was announced and premiered on Japanese television in July 2021.
It was just a usual morning. Shiroyanagi Akira, a high schooler who loves games and Konpeito (Japanese sweets), has suddenly been dragged into a battlefield by a mysterious girl who calls herself Mion. The participants are told that they are "erased from the family register, involved in an experiment, and gained certain powers."
Akira is determined to win the game with his newfound powers and destroy the organization. Armed with a power no one expects and his "brain" skills, the new period of intelligence battle of begins!