Professor Rowan's assistant. Secretly she's a runaway from Team Galactic.
- Age Lift: In the first chapter of the Spin-Off, Mitsumi's surprised to know that Hareta is actually a little older than her (she has yet to turn 15). In the Diamond And Pearl Adventures manga, she was implied to be a young adult or at least in her late teens.
- Chekhov's Gunman: First appeared in the Argenta oneshot, is a main character in The Wild Boy from Sinnoh.
- Foil: She's this to Hareta. She's an experienced Pokémon trainer and has a very analytical mindset for battling. She's also very cynical due to her experiences with Team Galactic, contrasting with his happy-go-lucky nature.
- Identical Stranger: Resembles Dawn extensively, though the exact reason as to why is unknown.
- Playing with Fire: Her main Pokémon is her Infernape.
- Red Oni, Blue Oni: The blue to Hareta's Red, being more analytical and cautious than him.
- Worthy Opponent: Argenta sees her as one when her Infernape ties against her (very powerful) Pachirisu.
- Younger Than They Look: Is younger than she lets on.
A young man from Sinnoh who grew up in the wild, raised by a family of Pokémon and a researcher named Kaisei.
- Attack! Attack! Attack!: His battling style comes down to this.
- ¨Calling Your Attacks: When he battles Roark, he's prone to give some of his Pokémon attacks some cool-sounding names, like "Gravity-Powered Double Kick" and "Mega Volcanic Bide".
- The Empath: He calls his secondary bloodline "Empathy Exchange", and it allows him to transmit his emotions to people and Pokémon.
- Fish out of Water: Being raised by Pokémon means he's not very good at interacting with other people.
- Foil: To Mitsumi. While he displays a natural talent to be a Pokémon trainer, he's still very inexperienced when it comes to actual battling. He's a lot more optimistic than Mitsumi, and while he misses his father he's convinced they'll eventually meet again.
- Making a Splash: Professor Rowan allows him to keep a Piplup as his starter.
- The Nose Knows: He's able to find his way to Lake Verity by smelling the air.
- Older Than They Look: Looks younger than the fifteen he is.
- Pint Sized Power House: Despite his small size, he's strong enough to hold off an Onix with his bare hands
- Red Oni, Blue Oni: The red to Mitsumi's blue, being more upbeat and optimistic.
- Shock and Awe: Catches a Shinx in chapter 3 of his sidestory.
- Teens Are Short: Extremely short for his age, which is very rare considering he might be amongst Ash's possible half-siblings, who tend to avert this trope.
The local professor of Sinnoh region. According to some people, his standards for giving Pokedexes are not as high as other professors.
- Grumpy Old Man: Downplayed. Due to his expression he might come across as this at first, but he's actually very nice to those who know him.
A former Coordinator from Sinnoh, and Dawn's mother. Her whereabouts are currently unknown.
- Adaptational Angst Upgrade: As shown in Johanna Gaiden, she's had a rougher life than her canon counterpart.
- Ambiguously Bi: She mentions not minding if either men or women checked her out, though it is not clearly shown if that means she reciprocates both.
- Multi-Ethnic Name: Her mother had the maiden name Ayoko Platinum, which combines a Japanese first name with a surname derived from Spanish. It also references Johanna's Japanese name with Dawn's Adventure counterpart
- Named by the Adaptation: She's given the surname Berlitz.
- Oh, Crap!: She has this reaction in the championship round of the Grand Festival, after her opponent Mega Evolves their Medicham. Since Mega Evolution is generally used by trainers rather than coordinators, so she's never had a chance to practice dealing with it. It certainly doesn't help that her second Grand Festival loss came from a Mega Evolved Lopunny.
- Shoot the Shaggy Dog: Despite winning a Grand Festival and getting enough money to get surgeries for her parents, it wasn't enough to save them, and she ended up in serious financial strains afterwards.
A mysterious trainer who uses Legendary Pokemon. He fought Casey Snagem during his Sinnoh Run and is considered the peak of Sinnoh power creep.
- Been There, Shaped History: Tobias created Christmas.
- I Need a Freaking Drink: Tells Clembot to find him a world with rum when he learns that he was the one who created Christmas.
- Mysterious Past: Lampshaded by Ash's dreams as Ash comments he doesn't even know where the guy is from.
- Put on a Bus: Tobias in story's current location is unknown, though it is hinted he is off looking for a Celebi. Meaning he's likely lost in the woods somewhere, or flung through time. The latter is confirmed in the Clair Interlude, where it is revealed he is wandering the multiverse as a result.
- You Can't Go Home Again: Everytime he tries, Celebi will fling him across time and space.
Shotaro "Sho" Inazuma
A trainer from Sinnoh who prefers Electric-type Pokémon. Looks up to Volkner and seeks to become a great Electric-type specialist like him by challenging others.
- Ascended Extra: Was only a Character of the Day in a single episode in the anime.
- Battle Couple: His Raichu and Pikachu are mates.
- Blow You Away: Had his Rotom in Fan form at one point.
- Determinator: It took him four tries to defeat Volkner, but he succeeded.
- Deuteragonist: Of Gardenia's interlude.
- Extra-ore-dinary: His Raichu knows Iron Tail.
- Fire-Forged Friends: With Gardenia after they save Cheryl.
- Green Thumb: Had his Rotom in Mow form for a while.
- Hero-Worshipper: He looks up to Volkner, and to a lesser extent to other Electric-type specialists in general.
- An Ice Person: His Manectric knows Ice Fang, and for a while had his Rotom in Frost form.
- In-Series Nickname: Everyone just calls him "Sho".
- Man Bites Man: Aside from the fact that his Luxray and Manectric know Fang moves, the latter is known for chomping on people's hands to show affection.
- Meaningful Name: His surname "Inazuma" translates into "Lightning" in Japanese.
- Named by the Adaptation: "Sho" is just short for Shotaro Inazuma.
- Playing with Fire: His Luxray knows Fire Fang, and his Manectric knows Flamethrower.
- Power at a Price: His Manectric gains a lot of raw power with the Mega Evolution, but in exchange loses his Lightning Rod ability.
- The Power of Friendship: Thanks to Jasmine's advice, he finally bonds enough with his Manetric to control its Mega Evolution.
- Shock and Awe: Prefers Electric-types.
- Super Mode: Receives an Electrike carrying a Manectrite. He eventually evolves it and gets a Key Stone, gaining access to Mega Evolution.
- Tail Slap: His Raichu knows Iron Tail.
- You Have GOT to Be Kidding Me!: His reaction when he finds out that Alolan Raichu are real.
A treasure seeking young woman and friend of Gardenia.
- Color Motif: Green, like in canon.
- Constantly Curious: According to Gardenia, she often gets into trouble for this.
- Damsel in Distress: Kept in a Lotus-Eater Machine by the ghosts of the Old Chateau.
- Rapunzel Hair: Even while tied in a braid, her hair is very long.
- Statuesque Stunner: She's as tall as Sho, who's a head taller than Gardenia.
- Treasure Hunter: Like her grandfather before her.
A young recruit of the International Police, and Looker's partner during their mission in Sinnoh.
- Berserk Button: Mistreating Pokemon makes him nearly murderously angry.
A young freelance researcher who has collaborated with Pokémon Professors, widely respected thanks to his knowledge about Legendaries.
- Disappeared Dad: To Hareta.
- Named by the Adaptation: He's given the surname Yamamoto in this story.
- Unrelated in the Adaptation: Assuming that Hareta is the son of the brother from Orre spreading his seed around, he is most likely his adoptive father in this universe.
The assistant of Prof. Newton Graceland, interested in finding the Distortion World.
A Ice-type Trainer from Sinnoh and a former student of the Snowpoint Gym.
- An Ice Person: She's an Ice-type specialist.
- Icy Blue Eyes: Fitting for an Ice-type trainer.
- Statuesque Stunner: Quite tall and has a nice figure.
- The Worf Effect: Her role in story is primarily to prove (to Paul and the audience) that Erika is powerful and fully bury the idea that one can run over a gym with a super effective typing.
- You Gotta Have Blue Hair: Silvery-blue, to be exact.
A former trainer turned breeder from Veilstone City. Paul's older brother.
- Nice Guy: According to Maylene, sometimes he's too nice for his own good.
- Noodle Incident: Apparently he got into several Bar Brawls back in his days as a trainer.
- Platonic Life-Partners: Has this dynamic with Maylene, treating her like a little sister.
- The Rival: Was this to Casey Snagem years ago.
A veteran Pokémon Researcher. Became Cynthia's mentor after she saved her and her archaeologist team of a hostile Spiritomb.
Oreburgh City's Gym Leader, who specializes in Rock-type Pokémon. Byron's son and grandson of Elite Four member Bertha through his mother Roberta. He also knows Kaiser.
- The Cavalry: He, his Pokémon and a couple of officer Jennies arrive in time to help Hareta and Mitsumi defeat the remaining Team Galactic grunts.
- Dishing Out Dirt: Rock-type specialist.
- Fossil Revival: Like in canon, his main Pokémon is Cranidos. And his parents give him an Archen for Christmas.
- Related in the Adaptation: He's the grandson of Elite Four member Bertha.
Eterna City's Gym Leader, who specializes in Grass-Type Pokémon.
- Fire-Forged Friends: With Sho when they work together to save Cheryl.
- Genre Savvy: She's seen enough horror movies to know that splitting up in a Haunted House is a very bad idea.
- Green Thumb: Grass-type specialist.
- Heterosexual Life-Partners: With Cheryl.
- Ms. Fanservice: She posed for a swimsuit calendar.
- "Not Making This Up" Disclaimer: Sho thought she was joking when she mentioned Alolan Raichu.
- Too Kinky to Torture: Freely lets her Carnivine chomp on her head, and enjoys it.
- Why Did It Have to Be Snakes?: Scared of Ghosts and Ghost-type Pokémon, but she's willing to brave her fears for Cheryl's sake.
Pastoria City's Gym Leader, who specializes in Water-Type Pokemon.
Hearthome City's Gym Leader, who specializes in Ghost-Type Pokemon.
- Gratuitous French: Like in canon.
- Ms. Fanservice: She posed for a swimsuit calendar.
- Our Ghosts Are Different: Ghost-type specialist.
Veilstone City's Gym Leader, who specializes in Fighting-Type Pokemon.
- Bare-Fisted Monk: Fighting-type specialist, plus she also practices martial arts.
- Does Not Like Shoes: As per canon.
- Exposed to the Elements: She's capable of training outside during a snowy day in her usual clothes.
- Platonic Life-Partners: With Reggie.
- Pointless Band-Aid: Averted in her interlude since she was sucker-punched in her nose.
- Teens Are Short: Despite being 19 and a half, she's rather short.
Canalave City's Gym Leader, who specializes in Steel-Type Pokemon. He's also the father of Orenburgh City's Gym Leader Roark. He likes fossils.
- Action Dad: A father and a Gym Leader.
- Extra-ore-dinary: Steel-type specialist.
- Fossil Revival: Like in canon, he uses some of this.
- Named by the Adaptation: His wife is given the name Roberta.
- Related in the Adaptation: Through his wife, he's the son-in-law of Elite Four member Bertha.
Sunyshore City's Gym Leader, who specializes in Electric-Type Pokemon. He's childhood friends with Elite Four member Flint.
- The Ace: He's considered the strongest Gym Leader in the Sinnoh region and his win percentage of 97% give some good credentials. Is also handsome, and an accomplished electrical engineer who renovated Sunnyshore City's power grid.
- Challenge Seeker: Since childhood, he'd been looking for strong opponents to battle.
- Friendly Rivalry: He and Flint had this when they were kids.
- Genius Bruiser: Along with the tactical acumen as to be expected of one of the strongest Gym Leaders, he's also an accomplished Electrical Engineer who helped rennovate Sunnyshore's power system.
- The Grinch: Isn't enthusiastic about Christmas, partly because he feels under-appreciated for the work he does to get Sunyshore ready for the season. As a child he had a similar feelings due to the fact there was nobody he could battle with. Though he grows out of this after training Sho for a while.
- Heterosexual Life-Partners: With Flint.
- The Mentor: He offers to become this to Sho after their fourth battle, and Sho accepts.
- Pretty Boy: Elesa referred to him as handsome several times in her gaiden.
- Red Baron: The Shocking Star from Sunyshore.
- She's Not My Girlfriend: Denies being attracted to Elesa. Openly at least.
- Shock and Awe: Electric-type specialist.
- Took a Level in Cheerfulness: He's a lot happier during the Christmas following his defeat against Sho, even accepting an invitation to have dinner with the Inazuma family.
- Victory Is Boring: A gym leader with a high win record, and low job satisfaction. Though Sho was able to snap him out of his funk by the end of his Interlude.
- Worthy Opponent: He sees Elesa as one after defeating her at the Gym Leaders Tournament. He also comes to see Sho as one after he finally defeats him.
One of Sinnoh's Elite Four, who specializes in Fire-Type Pokemon. He's also childhood friends with Volkner.
- Bedsheet Ghost: What his act as the Ghost of Christmas Past amounts to.
- Epic Fail: How his attempts to cheer up Volkner turned out. During Year One, Volkner quickly sees through his disguise. The next year, he's not even depressed to begin with.
- Fiery Redhead: Uses Fire-types and has red hair.
- Friendly Rivalry: As kids, he and Volkner had this.
- Heterosexual Life-Partners: With Volkner.
- Playing with Fire: Fire-type specialist.
- Serious Business: His yearly 'Three Christmas Ghosts' act is this, to the point he gets outraged when Volkner tries to do it himself and does it wrong.
- Yet Another Christmas Carol: Tries to invoke this on Volkner to cheer him up, but he fails.
One of Sinnoh's Elite Four, who specializes in Ground-Type Pokémon.
- Dishing Out Dirt: Ground-type specialist.
- The Ghost: Hasn't made an appearance yet.
- Never Mess with Granny: Obviously being an Elite Four. Bonus points for being an actual grandmother to Roark.
- Related in the Adaptation: Twofold example. She's confirmed to be Agatha's cousin, and also Byron's mother-in-law.
Sinnoh's current champion. A passionate treasure hunter and adventurer since she was a child.
- Adventurer Archaeologist: Eventually grows into this.
- Badass Adorable: At age 10 or 11, she was capable of doing a good Indiana Jones or Lara Croft impression.
- Cowardly Lion: Her Riolu is rather panicky and fearful, but always rises to the occasion.
- Famed in Story: As champion of Sinnoh.
- Hair of Gold, Heart of Gold: Blonde-haired and a very kind person.
- Im A Doctor Not A Place Holder: In response to a remark of Gible in her gaiden sidestory, she says "I am an aspiring Treasure Hunter, not a whatever kind of person maps ocean currents."
- Lady of War: An amazing battler, but still carries her air of grade and beauty.
- Little Miss Badass: As a child, not only was she an adventurer, she was even able to beat the tar out of older bullying kids.
- Make Me Wanna Shout: Her Riolu has an unusually powerful Screech attack.
- Missed the Call: Was Arceus' first choice to send back in time to save the world, but he couldn't save her in time.
- Ms. Fanservice: Posed for a swimsuit calendar.
- Nightmare Fetishist: As a child, she seemed a little too excited about a mass grave of dangerous criminals...
- Statuesque Stunner: She's pretty tall and very beautiful.
- Unwitting Instigator of Doom: Finding the Adamant Orb would later lead to problems for many down the line when contact with it caused a priest to go insane and go on a murderous rampage.
Hall Matron Argenta
A veteran trainer and former Sinnoh champion. Comes out of retirement in response to seeing too many trainers adhering to Smogon tactics in the latest Lily of the Valley tournament.
- Cool Old Lady: Is 68 and a former Sinnoh champion, several times League Conference winner and runner-up in a Sinnoh Grand Festival. She's so skilled even now that she defeats 399 trainers in a tournament using only a Pachirisu.
- Glory Seeker: Self-admitted, though it's more about trying new things and having adventure and excitement in her life.
- Jerkass Realization: She organizes a tournament in response to too many trainers using Smogon tactics in the latest Sinnoh Conference, due to the lack of variety and thinking of them as "Stop Having Fun" Guys. At the end, she realizes she has been trying to force her own views on Pokémon training on everyone, and decides to approach the problem in a more friendly manner, by creating the Battle Hall.
- Killer Rabbit: More like squirrel. Argenta's Pachirisu is skilled enough to defeat a freaking Garchomp, and that's just the beginning of her day.
- Never Mess with Granny: See above.
- Red Baron: By the time of the Sho Interlude, she's already taken the title of "Hall Matron".
- Retired Badass: She had retired after a lifetime of adventure, but comes back to create the Battle Hall.
- Scrub: She was disgusted by the little variety she saw at the latest Lily of the Valley conference, but after meeting Mitsumi, she realised her initial methods were too harsh and decided to tackle the issue from a friendlier approach.