I've updated the Supporting Characters and the Significant Others with the Japanese names and one or two other characters. Here they are:
Supporting Characters
2|Professor Oak||1|Dr. Yukinari Ōkido
2|Professor Elm||119|Dr. Utsugi
2|Professor Birch||277|Dr Odamaki
2|Delia Ketchum||1|Hanako
2|Officer Jenny||2|Junsa
2|Nurse Joy||2|Jōi
2|Gary Oak||1|Shigeru Ōkido
2|Professor Rowan||469|Dr. Nanakamado
Significant Others
3|Todd||053|Tōru
3|Ritchie||080|Hiroshi
3|Scott||409|Enishida
3|Drew||309|Shū
3|Harley||380|Harley
3|Casey||120|Nanako
3|Flint||005|Munō|Brock's Father
3|Forest||005|Jirō|Brock's Brother
3|Professor Ivy||084|Dr. Uchikido
3|Caroline||279|Mitsuko|May and Max's Mother
3|Harrison||267|Hazuki
3|Tyson||402|Tetsuya
3|Morrison||395|Masamune
3|Macey||269|Moe
3|Lilian||420
3|Paul||470|Shinji
3|Johanna||469|Ayako|Dawn's Mother
3|Mr. Sukizō||289|Sukizō-san|Contest Judge
3|Raul Contesta||289|Contesta|Main Contest Judge
I've also edited my last post with alot of the characters japanese names.
EDIT:
I've updated the Gym Leaders/Elite Four/Frontier Brains with their Japanese names. I've also added the first two Shinou Gym Leaders. Here they are
Gym Leaders
Kanto:
5|Daisy, Lily and Violet||007|Sakura, Botan and Ayame|Misty's Sisters
5|Lt. Surge||014|Machisu
5|Sabrina||022|Natsume
5|Erika||026|Erika
5|Koga||032|Kyō
5|Blane||058|Katsura
Orange League:
5|Cissy||087|Atsumi
5|Danny||095|Dan
5|Rudy||105|Jigī
5|Luana||110|Ruriko
5|Drake||113|Yūji
Johto:
5|Falkner||133|Hayato
5|Bugsy||146|Tsukushi
5|Whitney||160|Akane
5|Morty||183|Matsuba
5|Chuck||211|Shijima
5|Jasmine||210|Mikan
5|Pryce||238|Yanagi
5|Clair||253|Ibuki
Hoenn:
5|Roxanne||291|Tsutsuji
5|Brawly||296|Tōki
5|Wattson||316|Tessen
5|Flannery||331|Asuna
5|Norman||279|Senri|May & Max's Father
5|Winona||360|Nagi
5|Tate & Liza||375|Fū & Ran
5|Juan||387|Adan
Shinou:
5|Roark||483|Hyouta
5|Gardenia||499|Natane
Battle Frontier Brains:
5|Noland||412|Datsura
5|Greta||426|Kogomi
5|Tucker||430|Heath
5|Lucy||435|Azami
5|Spencer||440|Ukon
5|Anabel||446|Lila
5|Brandon||454|Jindai
Elites:
5|Bruno||073|Shiba
5|Lance||237|Wataru
5|Prima||101|Kanna|AKA Lorelei
5|Drake||378|Genji|Hoenn Elite Four
5|Agatha||409|Kikuko
EDIT 2:
Some more updated Misc Characters:
4|Old Man Swampy||301|Numaji
4|Keanu||303|Kazuki
4|Shauna||306|Shinobu
4|Robert||311|Robert
4|Marius||312|Yousuke
4|Captain Stern||312|Kusunoki
4|Elissa||314|Izuna
4|Thatcher||314|Kazuchi
4|Alanna||315|Akina
4|Natasha||317|Natchi
4|Romeo||318
4|Juliet||318
4|Michelle||319
4|Colonel Hansen||320|Hanzō
4|Princess Sara||320|Osashi
EDIT 3:
Even more updated Misc Characters:
4|Eliza||323|Arisa
4|Grace||326|Grace
4|Julie||329|Yoko
4|Old Man Moore||331|Mura
4|Watt||316|Watto
4|Dr. Abby||336
4|Timmy Grimm||337|Kimimaro
4|Mrs. Grimm||337|Kimyo
4|Mr. Morita||340
4|Professor Jacuzzi||341|Shakuji
4|Poncho||343|Poncho
4|Oscar & Andi||348|Oscar & Andrew
4|Sullivan||351|Suzumura
4|Calista||352|Kuruyo
4|Savannah||353
4|Sandra||353
4|Sonny||354|Sukisoh
4|Volt||356|Volt
4|Shane||356|Kite
4|Brody||359|Ban'nai|Team Magma Member
4|Elijah||362|Takaya
4|Marcell||364|Makino
4|Ralph||366|Jinbei|AKA Vladimir the Attacker
4|Kelly||366|Kanata
4|Jimmy||368
4|Keith||371|Kikuma
4|Nancy||371|Namiko
4|Rocky|372|Iwashimizu
4|Samantha||382|Sayuri
4|Gordon||384|Satoru
4|Nicky||384|Noboru
EDIT 4:
The rest of the Misc Character list, updated:
4|Jump||403
4|Vivica||403|Yuriko
4|Gilbert||403|Genki
4|Dominic||404|Tomomo
4|Gavin||404|Garon
4|Johnny||405|Ji'onbi
4|Katie||405|Kaede
4|Clark||405|Hyūga
4|Emily||417|Azumi
4|Rhoda||418|Res
4|Rhonda||418|Tauran
4|Xander||419|Zenkiti
4|Terri||422|Tsuguyo
4|Kyle Hamm||422|Kyoutarou
4|Master Hamm||422|Hamaguri
4|Cadee||425|Sakie
4|Mariah||425|Momoko
4|McCauley||425|Ryuta
4|Nicholette||427|Shiromi
4|Jeremy||428|Ogata
4|Tiffany||429|Hisame
4|Mr. Saridakis||429|Namidabashi
4|Brianna||439|Wakana
4|Yuma||444|Yuma
4|Solidad||456|Saori
4|Audrey||460
I'm not sure if the characters below are the English or Japanese names, so i'm not sure what to do.
4|Luna||443
4|Hiroshi||443
4|Mika||444
4|Kinya||449
EDIT 5:
Updated and added to the movie character list:
4|Corey||Movie 1|Sorao
4|Fergus||Movie 1|Umio
4|Neesha||Movie 1|Sweet
4|Kezoki||Movie 1
4|Dr. Fuji||Movie 1|Fuji-Hakase
4|Miranda||Movie 1|Boija|Harbour Master
4|Lawrance III||Movie 2|Jirarudan
4|Melody||Movie 2|Furuura
4|Lisa||Movie 3|Rin
4|Molly Hale||Movie 3|Mii Snowdon
4|Professor Spencer Hale||Movie 3|Shurī-Hakase Snowdon
4|Skyler||Movie 3|Jon
4|The Pokémon Hunter||Movie 4
6|The Iron Masked Marauder||Movie 4
6|Annie & Oakley||Movie 5|Zanna and Rion
4|Butler||Movie 6
4|Diane||Movie 6
4|Brendan||Movie 6
4|Tory Lund||Movie 7|Toh'i
4|Professor Lund||Movie 7|Rondo-Hakase
4|Rebecca||Movie 7|Hitomi
4|Rafe||Movie 7|Ryū|Brother to Audrey & Catherine
4|Sid||Movie 7|Shouta
4|Audrey & Catherine||Movie 7|Audrey & Catherine
4|Yuko||Movie 7|Yūko|Professor Lund's Assistant
4|Lady Eileen||Movie 8
4|Kid Summers||Movie 8|Kid Summers
4|Sir Aaron||Movie 8|Aron-sama
4|Jack Walker||Movie 9
4|Phantom||Movie 9
4|Lizabeth||Movie 9|Hiromi
EDIT 6:
More Misc characters:
4|Jeanette Fisher||079|Kaoruko
4|Sunrisa||137
4|Koji||143
4|Timothy||193
4|Raiden||196
4|Jack Pollockson||199
4|Skyler||204
4|Pietra||206
4|Captain Marius||212|Kaidō
4|Mika||215
4|Andrea||215
4|Lokoko||234|Rokoko
4|Kiyo||235|Nobuhiko
4|Steven||241|Saiga
4|Lily||243|Lily
EDIT 7:
More Misc Characters:
4|Satchel||264
4|Nando||472|Naoshi
4|Clara||473|Yukino
4|J|28|488|J|Pokémon Hunter
4|Abigail||492|Amano
4|Minnie||476|Minae
4|Landis||478|Teruhiko
4|Haley||489|Hatsune
4|Oralie||489|Otone
4|Melodi|16|488|Maria
4|Rosebay||481|Yukari
4|Theresa||492|Tamami
4|Forsythia||493|Tsubomi
And a Significant Other:
3|Zoey||479|Nozomi
Kengo is the childhood friend of Hikari, it is rumoured to be the anime counterpart of the yellow-haired guy from the game. he has a Prinplup as his Pokemon.
3|TBA|10|493|Kengo
I've just noticed that you have Kengo down as appearing in Episode 493. Episode 493 is The Gifted Roserade and the Flower Legend! whereas he apperears in Episode 494: Pokémon Contest! Sonoo Conference!.
EDIT 8:
Updated and added to the Team Rocket category:
6|Jessie||002|Musashi
6|James||002|Kojirō
6|Meowth||002|Nyarth
6|Cassidy||057|Yamato
6|Butch||057|Kosaburō
6|Giovanni||015|Sakaki
6|Dr Nanba||222|Dr Namba
6|Tyson||237|Tatsumi
6|Professor Sebastian||237|Shiranui-Hakase
6|Wendy||233|Jinjii
EDIT 9:
Misc Character:
4|Hank||459|Hiyoshi
I thought i'd add Brocks Siblings:
3|Salvadore, Yolanda, Tommy, Cindy, Suzie, Timmy, Billy and Tilly||5|Saburō, Yomoko, Gorō, Mutsuko, Nanako, Yaoki, Kurō and Tōko
EDIT 10:
Some Original Series Misc Characters:
4|Seymour||006|Rikao
4|Bill||013|Masaki Sonezaki
4|Moe||018|Ryū
4|Brutella||018|Obaba|Nastina's Cousin
4|Nastina||018|Obaba|Brutella's Cousin
4|Sabrina's father||022|Natsumi's father
4|Susie||028|Yuki
4|Antony||029|Asoki
4|Rebecca||029|Manami
4|Lara Laramie||033|Fūko Laramii
4|Dario||033|Dorio
4|Tommy||034|Tarō
4|Chopper||036
4|Tyra||036
4|Hippie||041
4|Yas Gym Leader||042
4|Kas Gym Leader||042
EDIT 11:
A few other Misc Characters:
4|Dr. Proctor||047|Dokuta Doku
4|Stella||064|Atsuko
4|Professor Westwood||068
4|Florinda Showers||070|Lindow Murasame
4|Potter||070
4|Cliven Speilbunck||071
4|Katrina||071
4|Eve||074
4|Mr. Charles Goodshow||076
4|Mandy||077|AKA The Astounding Mandy
4|Pete Pebbleman||078
4|Mateo||089|Isao
4|Marissa||089|Masami
This character never had a dub name:
4|||087|Senta|Brother of Cissy the Mikan Island Gym Leader