Sasuke is a college student and a history nerd who has made a hobby out of studying time slips. One day, he slips through one of these time slips and finds himself in the Sengoku Period, although it's nothing like what he's read about in the history books. He takes the name Sarutobi Sasuke and becomes a retainer of the infamous Oda Nobunaga. His first mission is to win the confidence of Nobunaga's other famous retainers, Toyotomi Hideyoshi and Tokugawa Ieyasu.

At one of the regular meetings of the warlords, Date Masamune appears and wants Sasuke to teach him something new for an upcoming poetry competition. Sasuke teaches Masamune and being a quick study the warlord takes to it instantly. The other warlords are inspired and each try their hand at their own rapping style.

As a spy for the Uesugi forces, Sasuke has been spying on the Oda Forces looking for a way to bring them down for his master. One of his suggestions is the idea of junk or spam mail, basically in an attempt to annoy Nobunaga and his men. The men write hundreds of letters and shoot them off, greatly underestimating the kind of men Nobunaga has in his service.

Uesugi Kenshin is not the only one seeking Nobunaga's down fall. The monk, Kennyo, also seeks revenge on Nobunaga and, thanks to some help from Akechi Mitsuhide, manages to sneak into Azuchi Castle. Things seem to be going smoothly until the attic he has snuck into turns out to be much more heavily fortified than he was led to believe.

Frustrated and fed up with their lack of progress, Uesugi wants to storm Azuchi Castle. Sasuke manages to quell his fury and asks for time in order to negotiate with Nobunaga, leaving Yukimura as a hostage for Uesugi if he doesn't return. Will Sasuke make it back in time to save his friend?