Amekawa Shintarou and his childhood friend, Haruna Natsuki, once inseparable, drifted apart due to Shintarou's obsession with an FPS game. Their close bond shattered into bitter exchanges whenever they crossed paths. One fateful day, Shintarou ventured into Natsuki's room after years of estrangement, only to discover her absence and a high-end gaming PC displaying the post-battle results of his own beloved FPS game. Shockingly, the username and kill count revealed Natsuki as 2N, the world's second-ranked sniper—a revelation that shattered Shintarou's disbelief and reunited him with his lost friend.