Magane Hyuga commanded the Imperial Japanese Navy's advanced battleship Ra during World War II. The Ra incorporated a mysterious energy source uncovered in the 1930s, later revealed as part of a Subterranean civilization test. In 1945, during a pivotal clash near Hiroshima against the American counterpart Liberty, both warships were destroyed following a direct collision. Magane ordered his lieutenant to evacuate the sinking Ra with the Subterranean defector Annette, while he remained aboard and was presumed dead.

Fifty years later, Magane resurfaced as commander of the secretly rebuilt Ra, restored over decades to counter the anticipated Subterranean invasion. His reappearance shocked his son Go, who believed his father perished in 1945 and now confronted him aboard the reconstructed vessel. This revelation fueled tension, stemming from Magane's prolonged absence due to unwavering commitment to his military mission.

Leading against the Subterranean forces under Avatar, Magane enforced steadfast leadership focused on tactical superiority and humanity's survival. His command prioritized the Ra's combat effectiveness during engagements with the Subterranean fleet and the reactivated Liberty. He demonstrated resolve by rejecting Annette's appeals for peaceful solutions against Avatar's aggression, reinforcing his dedication to military resolution as the primary means to end the threat.

Magane's operational background included overseeing the Ra's original construction and later spearheading its reconstruction. His expertise proved vital in deploying the battleship's capabilities, such as its frontal drill during the climactic battle against the Liberty, where the Ra successfully pierced the enemy vessel. His command tenure bridged both historical and contemporary phases of the conflict against the Subterranean civilization.