Hiroshi is a relaxed young man, killing some time through cooking until his life is suddenly endangered when a mysterious bomber tells him that his crew must disarm a bomb that threatens to destroy their ship.
Hiroshi is a young man with average build. His dark-colored hair is short and wavy, and he is often seen dressed very casually. While cooking, Hiroshi wears a flower apron.
Hiroshi is depicted as a cheerful and laid-back young man, albeit naïve at times. He seems to be very polite and friendly with his crewmates as he often offers things to Matt. However, he can quickly become aggravated in times of panic, such as during his interactions with the mysterious bomber.
One of Hiroshi's qualities listed in his introduction is being the ship's engineer. He is very familiar with the technology aboard the Dillinger. When Clyde was in the process of dismantling Virginia, Hiroshi was able to point potential dangers to his crewmate, Matt Jackson, and when a waterpipe burst in the block, he was able to quickly identity the cause.
Before becoming a crewmate of Dillinger, Hiroshi was a former soldier in the army. While nothing else is known about Hiroshi's life before his position on the Dillinger, he is known to carry a good luck charm, given to him by his mother.
Aboard the Dillinger, he fulfills the role of an engineer and chef, being second in command to the cargo ship to his Superior, Matt Jackson. While cooking with Clyde one day, he receives a trasmission from an unknown, nearby ship, only to be told that a bomb named "Virginia" has been placed on their ship. Hiroshi initially takes the threat as a joke, assuming the other person to be bored and wanting to play a prank.
Upon realization of the danger him and his crewmates are in, Hiroshi expresses a mix of shock and anger, rushing to inform Matt of the transmission. With the information they have, Hiroshi and Matt compose a plan of creating a vaccuum around the bomb and sending Clyde to disarm "Virginia". In the midst of sendng Clyde, Hiroshi offers the good luck charm, given to him by his mother, to Matt, who refuses it.
While Matt is directing Clyde in order to disarm the bomb safely, Hiroshi notices a waterleak nearby Clyde, a reprecussion of turning that section of the ship into a vacuum. Despite the danger of the water leak, the crew manage to disarm "Virgina", allowing Hiroshi and Matt to rest easy once again. Soon after Clyde's return, Hiroshi is seen brewing tea, offering some to Matt, who declines, claiming to go take a nap. Hiroshi responds that he will soon report the bomb back to their headquarters. While pouring himself another cup of tea, he is unexpectedly greeted by the mysterious bomber once again, infuriating Hiroshi as he demands their information and identity. The mysterious bomber then reveals that he is inside of the Dillinger, leaving Hiroshi in a state of confusion and shock. Upon further thought, Hiroshi realizes that the Bomber is his own captain, Matt Jackson.