From Bulbapedia, the community-driven Pokémon encyclopedia.
In the early Generation I and II games, many glitches contained Japanese Katakana and Hiragana text, most notably the ゥ. The English games were not supposed to contain any Japanese character sets, however, some characters were left behind within the coding. Below are the only characters programmed into the game.
Gen I
Blue's Main screen tiles at address 0x8800, Notice ァ, ゥ, and ェ below the Pokémon logo.
Yellow's overworld tiles at address 0x8800, Notice ぁ, ぇ, and ぉ on the last line.
Yellow's in-battle tiles at address 0x8000, Notice ァ, ゥ, and ェ on the second-to-last line.
Yellow's main screen tiles at address 0x8800, Notice ァ, ゥ, and ェ on the middle line, and ぁ, ぇ, and ぉ on the last line.
R/B
Maintiles
Address
|
Character
|
8E90
|
ァ (a)
|
8EA0
|
ゥ (u)
|
8EB0
|
ェ (e)
|
Overworld tiles
Address
|
Character
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Battletiles
Address
|
Character
|
8E90
|
ァ (a)
|
8EA0
|
ゥ (u)
|
8EB0
|
ェ (e)
|
Yellow
Maintiles
Address
|
Character
|
8E90
|
ァ (a)
|
8EA0
|
ゥ (u)
|
8EB0
|
ェ (e)
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Overworld tiles
Address
|
Character
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Battletiles
Address
|
Character
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Gen II
G/S
Gold's Main screen tiles at address 0x8800, Notice ぁ, ぇ, and ぉ on the last line.
Maintiles
Address
|
Character
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Overworld tiles
Address
|
Character
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Gold's in-battle screen tiles at address 0x8800, Notice ど on the bottom left.
Battletiles
Address
|
Character
|
9700
|
ど (Do)
|
Crystal
Crystal's Main screen tiles at address 0x8800, Notice ぁ, ぇ, and ぉ on the last line.
Maintiles
Address
|
Character
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Overworld tiles
Address
|
Character
|
9760
|
ぁ (a)
|
9770
|
ぇ (e)
|
9780
|
ぉ (o)
|
Battletiles
Address
|
Character
|
9700
|
ど (Do)
|