Samurai Jam: Bakumatsu Rock is a historical action-comedy anime set in the Bakumatsu period, a time of political upheaval in Japan just before the Meiji Restoration. The series blends historical events with music and fantasy elements, focusing on the Shinsengumi and their struggle against a tyrannical government that controls the masses through the power of music. In this world, the government forces the people to listen to "Heaven's Song," a melody that brainwashes them into submission. The protagonists, a group of rebellious rock musicians, use the power of rock music to fight back and inspire change.

The central characters are part of a rock band called Ultra Souls, which includes Ryoma, a passionate young man determined to use his music for revolution. They face off against the forces of the government, including their oppressive leader Ii, who is intent on using music to control the population. With themes of freedom, individuality, and rebellion, the series explores how the power of music can both oppress and liberate, creating a unique blend of historical drama and fantastical elements.

Throughout the series, the characters develop their bonds and beliefs as they encounter allies and enemies. The music acts as both a weapon and a symbol of resistance, with electrifying performances that resonate with the people around them. Samurai Jam: Bakumatsu Rock ultimately emphasizes the importance of standing up for one's ideals and finding the courage to fight for a better world, all set against the backdrop of a pivotal moment in Japan's history.