In the anime Mōretsu Atarō, the character known as Heart Boss's Henchman A is officially named Kopun A (コプンA). He is one half of a loyal duo that serves Kokoro Boss, alongside his constant companion, Kopun B. The pair of henchmen are almost always seen together, forming an inseparable and visually mismatched team, as Kopun A is notably the taller of the two. Their primary role within the story is to act as the ever-present attendants to Kokoro Boss, following him wherever he goes and assisting with his various whims and schemes.

Kopun A is characterized by his unwavering loyalty and faithfulness to his boss. He and Kopun B are depicted as being completely devoted, enduring the sometimes troublesome or eccentric hobbies and moods of Kokoro Boss without question. Their existence is defined by their service, and together they are known as the "Kopun," a play on the Japanese word for "subordinate" (kobun). Despite being a pair of tough-looking henchmen for a somewhat intimidating boss, they are also portrayed as hardworking individuals who are caught up in their leader's often strange and amusing antics. There is no significant individual character development or unique backstory for Kopun A alone, as his identity is firmly tied to his role as part of a comedic duo and as a loyal follower. His notable abilities are not combat-oriented but rather lie in his steadfast obedience and his function as a comedic foil to his boss's personality. The relationship between the two henchmen is one of partnership, often described as a "deformed and uneven pair" (dekoboko konbi), highlighting their contrasting statures but unified purpose.