TV-Series
Description
Eiji Hasegawa serves as the vice-captain of the First Division of the Defense Force, a unit recognized as the strongest among the divisions. Before the events of the main story, Hasegawa held the position of platoon leader, and it was in this capacity that he discovered a young Gen Narumi fighting a kaiju on his own, bringing him to the attention of the Defense Force. He has a birthday of August 24th.

Physically, Hasegawa is an imposing figure, standing 210 centimeters tall. He is bald and incredibly muscular, with distinctive red eyes that lack eyebrows, a light mustache, and numerous scars that attest to his extensive combat experience. The most prominent of these is a large scar over his left eye, with additional marks on the sides of his head and along his left jaw.

In terms of personality, Hasegawa is a highly professional and formal individual who takes his duties with the utmost seriousness. This rigid and unwavering demeanor often puts him at odds with the childish and carefree behavior of his captain, Gen Narumi. He is not afraid to scold or even physically discipline Narumi to maintain order and discipline within the division. Despite these clashes, their relationship is built on deep mutual trust and chemistry, with Hasegawa effectively managing the division's operations so that Narumi can perform freely on the battlefield. Due to his leadership and stern nature, Hasegawa is highly respected not only by the members of his own First Division but also by members of other divisions, such as Soshiro Hoshina, the vice-captain of the Third Division.

Hasegawa's primary role in the story is that of the steadfast leader of the First Division. He is often seen commanding the troops during battle, issuing orders, and ensuring the unit functions cohesively, which allows Captain Narumi to focus on engaging powerful kaiju without being bogged down by command responsibilities. He is present during key events, such as the introduction of Kikoru Shinomiya to the First Division after her transfer, and during meetings regarding the status of Kafka Hibino, also known as Kaiju No. 8. Hasegawa is also responsible for conveying important information to his captain, such as the emergence of kaiju attacks, and for keeping the captain focused on the mission at hand.

As vice-captain, Hasegawa's development is closely tied to his role as the anchor of the First Division. He is a seasoned veteran whose scars and authority speak to years of survival and leadership in the fight against kaiju. He effectively assumes many of the captain's administrative and disciplinary duties, correcting irresponsible behavior to keep the group functioning effectively. His primary development is in managing the dynamic with the eccentric Captain Narumi, ensuring that the strongest division lives up to its reputation.

In combat, Hasegawa wears the standard Defense Force combat suit, augmented by a large, stocky battle armor equipped with machine guns on the shoulders. He also uses a respirator mask during battles. His true strength lies not in superhuman abilities but in his powerful leadership skills, commanding the First Division with authority and firmness to ensure the coordinated effort required to take down massive kaiju threats. This ability to lead and be heard makes him a cornerstone of the First Division's effectiveness.