Piisuke is a small yellow parrot who appears in the anime Sakamoto Days as the constant companion and partner of the sniper Heisuke Mashimo, sometimes spelled Pisuke. He is easily recognizable by the belt of pouches worn around his neck, which he carries into battle as part of his supporting role. Despite being a bird, Piisuke functions as a genuine field partner rather than a simple pet, acting as Heisuke's spotter during missions and helping him line up his shots. The two display seamless teamwork in combat, with Piisuke assisting in complex sniper techniques such as ricochet shots from difficult angles.

In terms of personality, Piisuke is deeply loyal, affectionate, and emotionally attentive. He is devoted to Heisuke and regularly comforts him when his owner feels down or discouraged, which matters greatly because Heisuke struggles with low self-esteem and a lack of confidence outside of his marksmanship. Piisuke is also very affectionate and stays close to his owner at all times, providing emotional stability and companionship in both calm and dangerous situations. His motivations are simple and rooted in his bond with Heisuke: to stay by his side, support him, keep him company, and help protect him when fights break out.

Piisuke's role in the story is tied almost entirely to Heisuke's journey. When Heisuke is introduced, he is a struggling freelance assassin living in a damaged tent, and Piisuke is his only reliable companion. As Heisuke becomes involved with Taro Sakamoto and begins working at Sakamoto's store, Piisuke remains a fixture of his everyday life and a key part of his combat routine. In battle, the bird contributes as a spotter and support unit, giving Heisuke the information and assistance he needs to land precise shots and cover the group from long range. His presence also highlights the gentler side of Heisuke's character, since the sniper's tender and playful relationship with his bird contrasts with the violence of his profession.

Notable abilities include functioning as a highly effective spotter, carrying useful gear in the pouches around his neck, communicating with Heisuke during operations, and coordinating with him so smoothly that the two operate like a single unit on the battlefield. Beyond his practical skills, Piisuke's most significant trait is his unwavering devotion, which makes him a steady emotional anchor for Heisuke and a quietly important part of the team that surrounds Sakamoto.