Alright. I'm going to speed up the process of people using the Japanese
names. Did it take this long for Sailormoon? Oh well. I hope to add more
town, item, character, and attack names eventually.

Characters:

James/Kojirou
Jessie/Musashi
Ash/Satoshi
Misty/Kasumi
Brock/Takeshi
Giovanni/Sasaki
Gary/Shigeru
Professor Oak/Oukido-sensei
Cassandra/Kiyomi
Butch (shudder)/ Yamato
Cassidy/Kosaburo
Todd (Snap in Canada)/Touru

Items

Pokeball/Monster Ball

Towns

Pallet/Masara
Cerulean/Hanada

Attacks

Mega Punch/Megaton Panchi

Pokemon (This is a long one)
Pikachuu/Pikachu
Kairyuu/Dragonite
Yadoran/Slowbro
Pijon/Pidgeotto
Kodakku (Koduck)/Psyduck
Koratta/Ratatta
Zubatto/Zubat
Gyaroppu (Gallop)/Rapidash
Sandaasu (Thunders)/Jolteon
Menokurage/Tentacool
Pauwau (Powwow)/Seel
Karakara/Cubone
Tamatama//Exeggcute
Garagara/Marowak
Fushigidane/Bulbasaur
Aabo/Ekans
Iibui/Eevee
Utsudon/Weepinbell
Erebuu/Electabuzz
Kabigon/Snorlax
Kabuto/Kabuto
Saidon (Psydon)/Rhydon
Jugon/Dewgong
Porigon/Porygon
Deiguda (Digda)/Diglett
Doudorio/Dodrio
Gengaa/Gengar
Dogaasu (Dogase)/Koffing
Ruujura/Jynx
Nyaasu (Nyase)/Meowth
Shawaazu (Showers)/Vaporeon
Kusaihana/Gloom
Kokuun/Kakuna/
Goosuto (Ghost)/Haunter
Iwaaku (Iwake, or Ewok)/Onix
Hitokage/Charmander
Rakkii (Lucky)/Chansey
Ratta/Raticade
Onidoriru (Onidrill)/Fearow
Koiru (Coil)/Magnemite
Reakoiru (Recoil)/Magneton
Pukurin/Wigglytuff
Zenigame/Squirtle
Nyorozo/Poliwhirl
Tosakinto/Goldeen
Faiyaa (Fire)/Moltres
Buusutaa (Booster)/Flareon
Fuudein/Alakazam
Buubaa (Boober)/Magmar
Sutoraiku (Stryke)/Scyther
Kyatapii/Caterpie
Pikushii (Pixie)/Clefable
Shiidora/Seadra
Raichu/Raichu
Hitodeman/Staryu
Kurabu (Krab)/Krabby
Nidokuin/Nidoqueen
Sandoban/Sandslash
Azumaou/Seaking
Toranseru (Trancell)/Metapod
Doudou/Doduo
Tattsuu/Horsea
Gaadei (Guardie)/Growlithe
Mankii/Mankey
Dokukurage/Tentacruel
Onisuzume/Spearow
Sando (Sand)/Sandshrew
Parasekuto/Parasect
Suriipu (Sleep)/Drowzee
Biidoru (Beedle)/Weedle
Kairosu/Pinsir
Pijotto/Pidgeot
Koikingu (Koiking)/Magikarp
Saihoun (Psyhorn)/Rhyhorn
Matadogasu (Matadogas)/Weezing
Fushigisou/Ivysaur
Kamekkusu (Kamex)/Blastoise
Sherudaa/Shellder/
Sandaa (Thunder)/Zapdos
Rizaado (Lizard)/Charmeleon
Nasshii/Exeggcutor
Betobeton/Muk
Poppo/Pidgey
Utsubotto/Victreebell
Purin/Jigglypuff
Keshi/Abra
Betobetaa/Grimer
Garuura/Kangaskhan
Gyaradosu/Gyarados
Goroonya/Golem
Pippi/Clefairy
Ishitsubute/Geodude
Gorudakku/Golduck
Omunaito/Omanyte
Gorubatto/Golbat
Aabokku/Arbok
Nidoran mesu/Nidoran female
Nidoran osu/Nidoran male
Nazonokusa/Oddish
Nyorobon/Poliwrath
Kamonegi/Farfetched
Rapurasu/Lapras
Rafureshia (Refresher?)/Vileplume
Kabutopusu/Kabutops
Nidoriina/Nidorina
Bariyaado/Mr. Mime
Marumain/Electrode
Fushigibana/Venusaur
Parasu/Paras
Rizaadon (Lizardon)/Charizard
Konpan/Venonat
Yadon/Slowpoke
Metamon/Ditto
Goosu (Ghos)/Gastly
Biriritama/Voltorb
Yungeraa/Kadabra
Kinguraa/Kingler
Sawamuraa (Sawamuler)/Hitmonlee
Ebiwaraa (Ebiwaler)/Hitmonchan
Kairikii/Machoke
Suriipa (Sleeper)/Hypno
Gourikii/Machamp
Sutaamii/Starmie
Madatsubomi/Bellsprout
Putera (Ptera)/Aerodactyl
Nidoriino/Nidorino
Perushian/Persian
Hakuryuu/Dragonair
Myuutsuu/Mewtwo
Kyuukon/Ninetails
Supiaa (Spear)/Beedrill
Beroringa/Likitung
Batafurii/Butterfree
Dagutorio/Dugtrio
Nidokingu/Nidoking
Omusutaa/Omastar
Parushen/Cloyster
Nyoromo/Poliwag
Koroon/Graveler
Rokon/Vulpix
Kentarosu (Kentauros)/Tauros
Poniita/Ponyta
Monjara/Tangela
Miniryuu//Dratini
Wanrikii/Machop
Morufon (Morphon)/Venomoth
Kameeru (Kamer)/Wartortle
Uindei (Windy)/Arcanine
Furiizaa (FREEZA! uh, I mean Freezer)/Articuno
Okorizaru/Primeape
Myuu/Mew
New ones include Mariru, Togepy/Togepi, Buru, Kirei-hana, Hou-Hou, Donfan,
Happa, Honoguma, Rediba, Kurusu, Yadokingu (Yadoking), and Tenryuu. If
you're wondering about Pikablu, that is the incorrect name, made up when
nobody knew Mariru's name, but saw the pictures. For more information about
Mewtwo and Mew, check out http://mewtopia.freehosting.net/. It has tons of
information about the movie featuring these two, and their characterization.
BTW, the movie hits US theaters November 15. I hope this has been a huge
help for those who wanted the Japanese names.