Hachizaemon Takeya is a fifth-year student at the Ninjutsu Academy, where he is fourteen years old and a member of the ro class. He serves as the acting chairman of the Biology Committee, a role he takes with great seriousness and responsibility, especially since there are no sixth-year students to lead the committee. His first appearance in the original manga was in the twenty-sixth volume, with his name being confirmed later in the thirty-ninth volume.

Takeya has a cheerful, friendly, and optimistic personality, often greeting others with his distinctive speaking habit of ohō. As the head of the Biology Committee, he is deeply committed to protecting wildlife from being harmed or hunted, a duty that earns him the respect of the younger, predominantly first-year, committee members. He firmly believes that keeping an animal comes with the responsibility to care for it until the very end. Any attempt to hunt wildlife in his presence will quickly enrage him. Despite his generally easygoing nature, he is known to remind fellow students, such as Magohei Igasaki, not to lose their pets, emphasizing the owner's duty to keep their animals safe.

His appearance is marked by notably messy, scruffy grey hair that he keeps tied up in a fluffy ponytail, and he has thick, triangular eyebrows. In the manga, it is revealed that he keeps bagworms living in his unkempt hair, which is his stated reason for not tidying it. His casual clothing consists of a sky-blue kimono patterned with a bamboo-leaf motif, a reference to the take meaning bamboo in his surname.

Among his classmates, Takeya is often associated with Heisuke Kukuchi, the acting chairman of the Dining Committee, and Kanemon Ohama, with the three sometimes referred to as the edible trio in fan discussions. He shares a strong bond with Heisuke, as they are both the only stand-in presidents for any committee at the academy. He was the last of the fifth years to experience Heisuke's famously difficult Tofu Hell dish; unlike his peers, he received a special platter of animal-shaped tofu that Heisuke created just for him, acknowledging his love of animals. Takeya also shares a brotherly relationship with Sanjirou Yumesaki, a first-year student whom he sometimes helps with homework.

In terms of abilities, Takeya wields a mijin as his specialty weapon. This is a chain with weights at its ends, used more for entangling an opponent than striking them directly. Reflecting his role on the Biology Committee, he keeps and raises various bugs and even a wolf. He lives alone in his cell at the academy, which is likely due to the large number of creatures he maintains.