Protagonists:
Ayane - The kunoichi has always been in love with Naruto, ever since they met when they were 12-years old. Assuming that Naruto does not feel the same for her, assuming it's because she's being Raidou's child, and jealous of the relationship he has with girls of noble families like Hinata, Moka, after everything they've been through together, she discards the purple headband he gave her and tries her best to rid herself of these feelings by staying away from him, hoping to use the distance to forget them entirely and move on. During Part III of Journey to Now, Ayane was given a letter by Kureha, Momiji's late older sister, telling her to open up about her feelings, something she just can't do.
Naruto Uzumaki - The Hero of the Fourth Great Ninja War, Naruto is tasked by Kirigiri to look into Haruka, Hayashi, Kouta and his gang. Prior to this, Naruto had been recovering his powers, having overused it during Naruto: METAVERSE. Unknown to Ayane, Naruto has genuine feelings for her, but after having his "forced upon" first time with Hinata, despite not feeling the same for her, he feels unworthy/undeserving of Ayane, feeling ashamed of himself, having these flings with other girls to mask his guilt. However, the thought of not having the purple-haired kunoichi at his side hurts more.
Supporting:
Kyouko Kirigiri - One of the founding members of Future Foundation and a member of the EDF (Earth Defense Force), Kirigiri has Naruto going after Kouta and his gang after a large shipment of UltraTech gear was "stolen".
Kasumi - Ayane's older half-sister, the two have slowly started patching up their relationship. Noticing her sister's change to her distant ways, Kasumi goes to Naruto, wanting to know what he did wrong, ultimately hearing Naruto's true feelings.
Hinami Fueguchi - A 14-year old girl whose parents hailed from the Uzumaki Clan, Hinami is Naruto's niece, being under his care after her parents were killed by ghouls. Whenever Naruto's not home, Ayane would be the one to take care of her, growing fond of the purple-haired kunoichi. With Ayane leaving, Hinami stays with Rito Yuuki, hers and Naruto's cousin.
Haru Okumura - An 18-year old college student and member of The Phantom Thieves, she is an old friend of Naruto's from when they were young. A month before Vulnerable Butterfly, she and the blond had a one-night stand. The blond also helped invest in Haru's cafe, which has become fairly popular.
Yui Kotegawa - A Sainan High student who harbors romantic feelings towards Naruto's cousin, Rito Yuuki, Kotegawa has formed a friendship with Ayane during the events of The Long-Lost Cousin. Noticing Naruto's sad look, she decides to give him some advice.
Kazuma Kiryu - Set before Yakuza 4, Kazuma Kiryu, a former member of the Dojima Family, informs Naruto on Kouta when the blond approaches him in Kamurocho, warning him of how dangerous a coward like him is. He may play a role near the end of the story.
Hotaruko Rinko - A high school student and soon-to-be runaway, Hotaruko finds herself being saved by Ayane, who tells her to get her act together and go back to her parents after beating on her (ex-)boyfriend, who happens to be a member of Kouta's gang.
Aiko Nakumura - A former lazy playboy, and the former heir to the Nakumura Family's multi-billion dollar fortune, Aiko left it all behind, leaving the inheritance to his younger brother Yuno, after their father died in a car accident looking for him, feeling the guilt of not reconciling with him. He has since become a professional race car driver using his dream of riding to forget. He finds himself involved with the fight against Kouta and his gang when Naruto, Hotaruko, and Ayane stop his car and make their escape from Kouta's hideout, being chased after.
Sal - A simple but capable car mechanic of American descent, Sal is Aiko's father-figure, as well as the main member of Aiko's pit crew.
Lorenzo - A young pit crew member, Lorenzo dreams of being a race car driver, looking up to Aiko. He has an infatuation for beautiful women and fast cars like his friend Aiko.
Trent Masterson - An American member of the Japan police force, Trent leads Naruto's Erebus Squad, a team given to him by Kyouko Kirigiri, after Ray's retirement, informing Naruto of cases the police can't handle or solve.
Ray Peters - A seasoned member of Erebus Squad, Ray retires to be with his wife and family. Though his role may be little, he is one of the driving forces for Naruto to go after Ayane.
Antagonists:
Hayashi - Hotaruko's ex and Kouta's ally, Hayashi is equally as dangerous as his boss, setting up the events in the story when Ayane saves Hotaruko from going with him. Though Kouta's the main villain in ART OF WAR, Hayashi shares the main antagonist spotlight with Kouta.
Kouta - A former member of the Tojo Clan, Kouta ran away from his former allies after being caught in the middle of a heinous crime, seeking protection from and joining the Yomei Alliance. Due to this new affiliation, he has connections to UltraTech and Talon, who provides the alliance the technology needed to crush the Tojo Clan and the Omi Alliance.
Haruka - Kouta's second-in-command, Haruka's a professional assassin with knife skills.
Ellis Kayden - Not entirely a bad guy, Ellis is an American-Japanese cop stationed in Kamurocho. He finds himself an informant for Kouta, who helps provide money for his family, mostly his older sister and ailing father. He becomes a somewhat important character in the story.
Doomfist - The leader of Talon, Akande Ogundimu possesses the Doomfist Gauntlet, which increases his great strength and agility.
Moira O'Deorain - A brilliant and controversial geneticist, Moira makes up part of Talon's inner council.