Yama Daiba, known as Logan in English releases and referred to as "Le narrateur," carries childhood guilt from an accident that paralyzed his brother Admiral Isora Daiba (Ezra) and critically injured their mutual love interest Nami. This trauma drives him to accept Isora's mission: infiltrate the spaceship *Arcadia* and assassinate Captain Harlock. During his infiltration, Yama gains Harlock's trust while witnessing the crew's loyalty and the captain's rebellion against the authoritarian Gaia Sanction. His perspective shifts when Harlock rescues him after Yama accidentally endangers a crewmate during temporal warhead deployment. Harlock's actions and philosophy of free will challenge Yama's loyalty to Isora. A pivotal revelation occurs when the *Arcadia* breaches Earth's defensive hologram, exposing the planet's desolate truth—hidden by the Gaia Sanction. Learning Harlock plans universal annihilation via spacetime collapse, Yama briefly allies with Isora against the captain. Yama's resolve solidifies upon discovering resilient flowers on Earth, contradicting the Gaia Sanction's narrative of absolute ruin. Nami's sacrificial death to end Isora's suffering further cements his rejection of both Harlock's nihilism and the Sanction's lies. He halts Harlock's execution, freeing the *Arcadia* crew to advocate for revealing Earth's truth instead of destruction. In the climax, Yama confronts Isora during a battle between the *Arcadia* and Gaia forces. After Isora dies shielding Earth from a particle cannon, Yama accepts Harlock's symbolic transfer of the detonator. Harlock departs, naming Yama guardian of the "Harlock myth." The *Arcadia*'s dark matter heals the crew, and Yama assumes command, inheriting the mantle of Captain Harlock. Outside the 2013 film narrative, Yama Daiba does not appear as narrator or protagonist in other franchise iterations like the 1978 series, *Endless Odyssey*, or *Gun Frontier*. His background, motivations, and arc remain unique to this storyline.