"Bakumatsu Rock -howling soul-" is set in an alternate version of Japan during the Bakumatsu period, where the Tokugawa shogunate enforces strict control over society through the use of "Heaven's Songs," a form of music that suppresses individuality and free thought. The shogunate's cultural dominance is maintained by the Shinsengumi, who act as enforcers of this oppressive regime. In this world, rock music is outlawed, and those who defy the shogunate's musical edicts face severe consequences.

The protagonist, Sakamoto Ryouma, is a passionate and rebellious musician who dreams of liberating Japan through the power of rock music. Alongside his bandmates, Hijikata Toshizou, Okita Souji, and Katsu Kaishuu, Ryouma forms the band "The Iron Heaven" to challenge the shogunate's control. Each member of the band brings their own unique personality and musical talent to the group, creating a dynamic and compelling ensemble. Hijikata, the stoic and disciplined bassist, contrasts with Okita, the playful and unpredictable guitarist, while Katsu, the calm and intellectual drummer, provides a stabilizing influence.

As the story progresses, The Iron Heaven gains popularity among the oppressed citizens, inspiring hope and rebellion against the shogunate's tyranny. Their performances attract the attention of the Shinsengumi, leading to confrontations and escalating tensions. The band's journey is fraught with challenges, including internal conflicts, personal sacrifices, and the constant threat of capture or death. Despite these obstacles, Ryouma and his bandmates remain determined to use their music as a weapon to awaken the people and overthrow the oppressive regime.

The narrative explores themes of freedom, resistance, and the transformative power of art, set against the backdrop of a historically inspired yet fantastical version of Japan. The characters' struggles and growth are central to the story, as they navigate the complexities of their mission and the personal stakes involved. "Bakumatsu Rock -howling soul-" combines historical elements with a modern twist, creating a unique and engaging tale of rebellion and self-expression.