When Sasuke Sarutobi, a regular college student fascinated by time slips, accidentally tumbles into one himself, he lands in the midst of the Sengoku Period. Surrounded by legendary figures like Toyotomi Hideyoshi, Tokugawa Ieyasu, and the notorious 'Demon King of the Sixth Heaven' Oda Nobunaga, Sasuke becomes a trusted vassal under Nobunaga's wing. Bringing contemporary ideas such as tennis matches and chain letters to these historical warlords, Sasuke navigates this ancient yet surprisingly fresh realm with ease.