TV-Series
Description
Hachi is a significant supporting character in the story, serving as the City Defense Operations Commander for the APE organization and the primary supervisor assigned to the young Parasites of Plantation 13. He is a tall, composed man with short, dark blue hair and a permanent, serious expression. A prominent vertical scar runs over his right eye, a physical mark of his past service that resulted in the loss of that eye during a brutal battle in the vicinity of Mars.

His background reveals that he was once a Parasite himself, piloting a FRANXX in the same unit as his colleague, Nana. It was during this time that he witnessed significant trauma, including the death of Nana's partner, which deeply affected her and contributed to his own eventual emotional suppression. The process of becoming a caretaker and commander, referred to as a Hachi, seemingly involved having his emotions muted or altered, making him an efficient but emotionally distant administrator. Despite this, fragments of his past, particularly his connection to Nana, remain a subtle undercurrent to his actions.

In his role, Hachi embodies a pragmatic and extremely dutiful personality. He is stoic, speaks in a direct and often stern tone, and almost never displays overt emotion or smiles. He adheres strictly to the rules and regulations set forth by the ruling APE council and refers to the children under his care by their code numbers rather than their chosen names, reinforcing his view of them as operational assets. His primary motivation is the successful execution of his duties: managing the defense of the city, analyzing combat data, and ensuring the Parasites remain capable pilots. He is not cruel, but he shows little outward sympathy, believing that the Parasites are tools of war with a predetermined, short lifespan.

However, Hachi is not entirely unfeeling. His motivations become more complex as the story progresses. He places significant trust in the eccentric Dr. Franxx, often following his directives that exist in a gray area of the official command structure. He also exhibits moments of genuine, if understated, concern. He takes the health of the Parasites seriously, showing worry when Mitsuru’s childhood injection of a dangerous elixir threatens his health or when Hiro is pushed to his physical limits. His steadfast loyalty to Nana is another key motivator. During a catastrophic attack, he physically shielded her from an explosion, suffering his grievous eye injury, and urged her to save herself while he stayed behind. This act reveals the depth of his buried feelings for her, forged in their shared past.

His key relationships are central to his character. His bond with Nana is his most significant. They share a long history, a mutual loyalty, and a partnership in overseeing the children. While her memories were altered after the trauma of losing her partner, Hachi retained his, serving as a silent, unemotional witness to her pain. Over time, their dynamic suggests a shared purpose that transcends their initial programming. He is also loyal to Dr. Franxx, acting as a conduit for the scientist’s plans, and maintains a professional, sometimes adversarial, relationship with the elite Nine squad, who report on his and Nana's activities to the APE leadership.

Throughout the narrative, Hachi undergoes a subtle but meaningful development. Initially a strict enforcer of APE’s will, he begins to show cracks in his cold demeanor. He does nothing to stop Kokoro and Mitsuru’s unauthorized wedding ceremony, and later expresses dismay when they are forcibly taken away and their memories are erased for this transgression. He admits to Nana that he wishes he had emotions so he would have known how to comfort the distressed children, demonstrating a clear desire to protect them that his conditioning prevented him from acting upon. In the final conflict, he actively works against the APE leadership to help the children. By the epilogue, having become immortal alongside Nana, he dedicates his existence to watching over the future of humanity and the new society the surviving Parasites build for themselves, showing he no longer views them as tools but as true people with their own futures. As a former pilot himself, he possesses combat experience and the strategic knowledge to command city-wide defenses and coordinate FRANXX squadrons effectively, having survived battles that would have killed most others.