Saemon Tachibana holds prominence as a Bunraku puppeteer in Japan, honored with the status of Living National Treasure for his exceptional mastery and contributions to traditional puppet theater. As grandfather to the series' protagonist Sakon Tachibana, he leads the Tachibana family, whose legacy runs deep in puppetry arts.

Saemon personally trained Sakon from youth in Bunraku’s techniques and philosophies, emphasizing that puppeteering intertwines with understanding human nature. His principle—"controlling a puppet is reading the heart"—demands fully embodying each character portrayed. This philosophy fundamentally shaped Sakon’s approach to both puppetry and detective endeavors.

A staunch traditionalist, Saemon upholds classical Bunraku disciplines and values. His mentorship extended beyond technical skill, instilling the conviction that ventriloquism and puppetry channel the "voice of the soul," enabling profound insight into human emotions and motivations. This foundational training later proves integral to Sakon’s crime-solving methods, particularly when reconstructing victims’ perspectives or confronting culprits through his puppet Ukon.

Though specific personal backstory remains undetailed, Saemon’s consistent role as mentor and cultural guardian anchors the narrative. He embodies the pinnacle of traditional puppetry artistry, his teachings perpetually guiding Sakon’s actions and growth. His legacy underscores the narrative’s thematic integration of Japanese cultural heritage.