Takeshi, once Pewter City's Rock-type Pokémon Gym Leader in Kanto, surrendered his position after losing to Satoshi. He then joined Satoshi's journey to pursue becoming a top Pokémon Breeder, showcasing his nurturing nature and deep Pokémon care knowledge. This included preparing specialized food and managing detailed maps and supplies for the group. Throughout the Diamond & Pearl series, Takeshi questioned his progress as a Breeder compared to his companions' tangible achievements. This introspection in Sinnoh led him to shift his goal towards becoming a Pokémon Doctor. A critical incident aboard a ship attacked by Dokukurage, where he cared for injured Pokémon without Nurse Joy, solidified this new ambition. He subsequently trained under Dr. Proctor in Pewter City before returning to Sinnoh to work at a Pokémon Center, aided by his Croagunk and a Blissey evolved from his Chansey. Characterized by maturity and serving as the group's voice of reason, Takeshi offered strategic battle insights drawn from his Gym Leader experience. His observational skills accurately assessed Pokémon's physical and emotional states. However, his composure frequently dissolved around women, leading to excessive flirtation. This often resulted in him being dragged away by companions like Kasumi or disciplined by his Croagunk's Poison Jab. Despite repeated rejections, he remained determined to find romance. His skills extended beyond medicine to proficiency in cooking, fishing, sewing, and cleaning, often managing group responsibilities. His preparedness was notable, carrying extensive supplies like books, Potions, and even a full tea set. He maintained strong family bonds, caring for younger siblings and respecting his father Flint, though he expressed frustration towards his mother Lola regarding her actions with the Pewter Gym. Following the Sinnoh journey, Takeshi appeared sporadically. He reunited with Satoshi in Alola wearing casual clothes and later attended the World Coronation Series finals in his Pokémon Doctor attire, accompanied by Croagunk and Blissey. He briefly rejoined Satoshi and others in the field, utilizing his signature resourcefulness and medical knowledge. His visual design evolved: his Diamond & Pearl outfit featured a green collared shirt, orange vest, khaki pants, and blue sneakers, while later appearances included a lab coat during medical work. Takeshi's eyes remained predominantly closed, a distinctive trait broken rarely for comedic effect, such as when affected by Pokémon attacks. His darker skin tone and spiky hair were consistent. His name derives from the word "rock," reflecting his original type specialization and role. Balancing comedic romantic pursuits with genuine dedication, Takeshi transitioned from Breeder to Doctor while maintaining his core identity as a reliable, knowledgeable companion supporting others and caring for Pokémon.