Masuda

Masuda is sociable, courteous and willing to engage openly with the German crew despite differences of language and nationality. He does not isolate himself as a formal military passenger.

He develops a particularly easy rapport with Ahbe. Masuda teaches members of the crew shogi and spends time playing with them during the long voyage, creating friendships in circumstances otherwise defined by military duty.

He also displays a strong sense of military honor shaped by the period and armed forces in which he serves. His response to the submarine's final crisis reflects those convictions.

Masuda is a trained officer of the Imperial Japanese Army and has studied aeronautics while stationed in Germany. The story does not establish extraordinary personal combat abilities comparable to Black Lagoon's modern gunfighters.

His specialist value lies in military knowledge and the aeronautical studies that originally brought him to Germany. He also carries a sword, consistent with his status as a Japanese officer during the period.

Masuda appears only in the anime's historical account of U-1324. The submarine's apparent final mission is to carry him from Germany toward Batavia, with Ahbe commanding the voyage.

Spielberger's late addition to the passenger list introduces the painting The Twelve Knights Led by Brunhilda, the object that will eventually bring modern criminals to the wreck. Masuda himself has no involvement in the later struggle over the painting.

American anti-submarine forces eventually cripple U-1324 with depth charges and leave it stranded on the seabed. With the vessel doomed and capture looming, Masuda commits seppuku using his sword.

Wentzel Ahbe is U-1324's captain and becomes Masuda's friend during the voyage. Masuda socializes with Wentzel Ahbe and his crew and teaches them to play shogi.

Spielberger travels on the same submarine but remains far more isolated. Masuda participates in the crew's social life while Spielberger largely stays in his quarters, emphasizing the difference between the two passengers.