Rear Admiral Issei Maebara commands the Imperial Japanese Navy's Deep Blue Fleet advanced submarine *Fugaku*, a key strategic naval asset. His leadership manifests decisively during combat, directing complex submarine maneuvers and ordnance deployment. In the critical Panama Canal mission, Maebara commanded the deployment of specialized marker dye to signal position and authorized encoded underwater sonic transmissions (Ontsuu-8) for emergency communication. He personally oversaw innovative "G-7" tactics, using decoy torpedoes releasing large air bubbles to mislead charging enemy destroyers. Maebara coordinated precise torpedo strikes based on sonar analysis and electronic calculations, targeting enemy vessels with oxygen-propelled torpedoes leaving no visible tracks.

Exhibiting calm confidence under pressure, Maebara instructed his crew to "take your time and do the math" for firing solutions, shifting between periscope-guided attacks and deep evasive maneuvers. Following successful engagements, he surfaced near enemy survivors in distress, acknowledging their presence while prioritizing mission requirements. His command balanced tactical aggression with calculated risk assessment.

Maebara personally selected approximately one thousand skilled crew for the Deep Blue Fleet's submarine division. He recruited specialists like Yokosuka Navy Band transfer Yamane Shuusuke, valuing his exceptional auditory capabilities for sonar. Fostering a command environment emphasizing technical proficiency, Maebara delegated tasks like torpedo selection to the torpedo chief during combat, combining disciplined oversight with trust in specialized expertise.

Ethical considerations influenced Maebara's operational choices. After surface combat exposed the *Fugaku* to enemy personnel in the water, he rejected machine-gunning survivors despite concerns about revealing the submarine's presence.