In order to emphasize his origins from the city Shigenori Soejima gave him accessories such as headphones and a bicycle as well as stylish hair. Little changes were made to his design in the making of the game.
Yosuke befriends the protagonist in the beginning of the game, and he is shocked to find that his friend Saki Konishi is the second victim of Inaba's murders. Noticing clues between the victims and the Midnight Channel, Yosuke and the protagonist go to the TV world to investigate her death. He ends up confronting his Shadow who represents his resentment of living in a small country town with little to do, as well as his inner wish for something exciting to happen. With help from the protagonist, Yosuke accepts his other self and forms the Investigation Team alongside him to know who killed Saki. His Shadow becomes the Persona Jiraiya (ジライヤ?), a red-scarved humanoid whose head vaguely resembles that of a cartoon frog decked with shuriken for eyes and on his hands, as well as bell-bottoms. In battle, Yosuke dual wields blades ranging from blunt wrenches to knives to daggers.
Throughout the player's interaction with Yosuke, he overcomes Saki's death and confronts his feelings about Inaba, accepting it as an enjoyable town despite his initial feelings. After this, Jiraiya evolves into Susano-o (スサノオ?), a humanoid wearing a blue jumpsuit surrounded by a large sawblade with a flame rising from his head. In the upcoming re-release Persona 4: Golden, Yosuke's Persona can evolve once more into Takehaya Susano-o (タケハヤスサノオ?), gaining a fireman's outfit, a large afro-like fireball spouting from his head, and sawblades beneath his feet. In the game's ending, he stays working in Junes, identifying the protagonist as his best friend.
Yosuke serves as the player's Social Link to the Magician Arcana (魔術師 Majutsushi?), representing action, initiative, and immaturity; in the animated series, Yu's friendship with Yosuke is signified by Yu's use of Pyro Jack (ジャックランタン Jakkurantan?). He appears in Persona 4 Arena using Jiraiya, and his nickname in the game is "Captain Resentiment" (キャプテン・ルサンチマン Kyaputen Rusanchiman?). During the events of Persona 4 Arena, Yosuke is now a third-year student at Yasogami High School and he begins to hear rumors that the Midnight Channel is back. When he decides to investigate, he meets a mysterious girl. He is voiced by Showtaro Morikubo in Japanese and Yuri Lowenthal in English. Lowenthal enjoyed playing Yosuke owing to the large number of events the character goes through despite being initially a comic relief. Takahisa Maeyama will portray him in the musical.