Born to a Choshu samurai family, he studied under Yoshida Shoin at the Shoka Sonjuku. In the Boshin War he served as a commander of imperial forces and went on to serve in the new government as State Councilor and Vice-Minister of Public Works. However, he harbored deep discontent with the Meiji government's modernization policies—particularly the abolition of samurai stipends and the introduction of conscription, which stripped the warrior class of its privileges—and in October 1876 he launched a rebellion in Hagi at the head of discontented former samurai (the Hagi Rebellion). The Hagi Rebellion was one of a series of samurai uprisings against Meiji modernization policies, alongside the Shinpuren Rebellion, the Akizuki Rebellion, and the later Satsuma Rebellion. But the rebellion was swiftly suppressed by government forces, and Maebara was arrested and executed on December 3 of that year. He was forty-two. As former allies Ito Hirobumi and Yamagata Aritomo rose to prominence in the Meiji government, Maebara chose a return to the old samurai way. His life—fighting to the end for 'justice' in accordance with Shoin's teachings—embodies the contradictions of the Bakumatsu-Restoration era.

A stubborn warrior who valued justice above all. He prioritized preserving his pride as a samurai and his mentor Shoin's teachings over adapting to the changing times. This rigidity ultimately led to tragedy.

The Hagi Rebellion was one of the anachronistic samurai uprisings of the era, but Maebara's attachment to 'justice' also symbolizes the values that Meiji modernization discarded. His determination to practice Shoin's teachings to the very end as a disciple of the Shoka Sonjuku is passed down to later generations.