Lieutenant Hide Yoshida serves as a police lieutenant in Ryme City, the unique metropolis where humans and Pokémon live as equals. He is a dedicated officer who worked closely with Detective Harry Goodman, the father of the film's protagonist, Tim Goodman. As a senior member of the Ryme City police force, Yoshida is portrayed as a professional and experienced investigator. His primary Pokémon partner is a Snubbull, a creature that, despite its tough and intimidating appearance, he affirms is adorable on the inside. This choice of partner reflects Yoshida's own personality, as he maintains a professional and somewhat stern demeanor while performing his duties, but is capable of showing genuine kindness and understanding in more personal situations.

Yoshida's role in the narrative is initiated by the tragic event that sets the story in motion: the apparent death of Harry Goodman in a car accident. He is the one who delivers this difficult news to Harry's estranged son, Tim, in Ryme City, and also provides Tim with the keys to his late father's apartment. During this initial meeting, he demonstrates a personal connection to Harry by assuring Tim that his father truly cared for him, noting that Harry was too busy with his work to express it properly. He also shows a moment of personal concern for Tim, asking why he does not have a Pokémon of his own and gently suggesting he not isolate himself during his time of grief.

When Tim later returns to the police station with the extraordinary claim that his father might still be alive, Yoshida acts as the voice of grounded reality. Relying on the official evidence, he refuses to believe Tim's theory and instead presents the surveillance footage of the car crash, using it as proof that no one could have survived the incident. This action highlights his role as a figure of official authority, bound by the evidence at hand.

Yoshida's key relationships are primarily with the Goodman family. His past partnership and friendship with Harry are evident throughout his interactions, as he speaks of the late detective with respect, calling him "the best of the best" and a "legend". This relationship establishes a foundation of trust between him and Tim, even when they disagree. Later in the story, during the climax at the Ryme City Pokémon parade, Yoshida is caught in the city-wide catastrophe when the R substance is released. He is among the citizens who are forcibly merged with their Pokémon partners, specifically with his Snubbull, before being restored to normal by Mewtwo. This event demonstrates that despite his authority and experience, he is not immune to the dangers that threaten the city.

While Yoshida does not have a significant character arc in the traditional sense, his role is one of providing emotional grounding and official perspective. His development is subtle, defined by his unwavering sense of duty and his underlying compassion, which motivates him to try and connect with Tim and honor the memory of his lost friend. His notable abilities stem from his position as a seasoned police lieutenant; he has access to case files, security footage, and the resources of the Ryme City police department. More importantly, his years of working with a partner like Harry have given him sharp instincts and a solid understanding of how detective work operates in their unique world, even if his own methods adhere more strictly to the official record.