"Sengoku Gakudō Nikki: Sensei no Chonmage" is a historical comedy anime set in a fictionalized version of Japan's Sengoku period, blending elements of time travel and school life. The story revolves around a group of modern-day high school students who are transported back in time to the 16th century. Upon arrival, they find themselves in the midst of the chaotic Sengoku era, where warlords and samurai vie for power. The students are taken under the wing of a peculiar yet wise teacher, Nobunaga Oda, who is depicted as a chonmage-wearing, eccentric figure with a deep understanding of both the past and the future.

The narrative centers on the students' attempts to adapt to their new surroundings while navigating the complexities of the era. They encounter historical figures such as Toyotomi Hideyoshi and Tokugawa Ieyasu, who are reimagined with comedic and exaggerated traits. The students' modern knowledge and skills often clash with the traditions and customs of the time, leading to humorous and sometimes perilous situations. Despite the comedic tone, the series occasionally delves into the challenges of survival and the moral dilemmas of altering history.

The main characters include the resourceful and quick-witted protagonist, who often takes on a leadership role among the students, and their classmates, each with distinct personalities and skills that contribute to their survival. Nobunaga Oda, the teacher, serves as both a mentor and a source of comic relief, frequently using unconventional methods to teach the students about the era and its values. The interplay between the students and historical figures drives much of the plot, as they work together to navigate the turbulent times while attempting to find a way back to their own era. The series balances humor, historical references, and lighthearted action, creating a unique take on the Sengoku period through the lens of time-traveling high schoolers.