Dai Gyakuten Saiban: Naruhodō Ryūnosuke no Bōken is the fourth entry of the Ace Attorney series on the 3DS and a spin-off prequel from the rest. It stars Phoenix Wright's ancestor, Naruhodō Ryūnosuke, when the concept of a defense attorney was new to Japan.
Naruhodō Ryūnosuke - the game's protagonist who's a second-year student at Teito Yūmei University. He has a strong sense of justice that gets him into trouble
Susato Mikotoba - A beautiful judicial assistant that works with Naruhodo. She has a progressive frame of mind and a love for law books and foreign mystery novels as well as sweets
Kazuma Asōgi - Naruhodo's close friend and fellow student at Teito Yūmei University. He is also studyinh to be a defense attorney though it seems he is more than qualified. He is the one who seeks to travel to Britain for his studies. He is calm and confident compared to Naruhodo
Sherlock Holmes - The Legendary English Detective that teams up with Naruhodo for criminal investigations
Iris Watson - a brilliant inventor and doctor who has invented rudimentary forensic tools for use in investigations. She is Holmes' assistant and in this universe, the author of The Adventures of Sherlock Holmes series.
Barok van Zieks - A cursed English prosecutor that has returned to the courtroom after a five-year absense