Double Yakuman [Model DMG-YVJ]

Credits:
At the title screen, hold either Left or Right, then press B.

Tile fetch editor:
At the title screen, enter the Credits screen as described in section above exactly 3 times, then start a 1-PLAYER game. During the game, before the tile is fetched, press Start to enter the Tile fetch editor. There are 16 numbers will be displayed on the screen. Use D-Pad button to select any of them, and A/B button to increase/decrease them. The numbers represents the custom tiles queue, which will be used first to select the next tile. Note, you can't see the other player's hand, so you may choose tiles already fetched, they won't be tossed to you obviously, the regular tile fetching procedure will be used instead. To be able to use the same cheat in SIMPLE MODE, you must enter the Credits screen 254 times instead.

Tile fetch cheat for 2-players mode:
At the title screen, enter the Credits screen as described in section above exactly 255 times, then start a 2-PLAYERS game. It somehow will adjust the tile fetching as well, but need to investigate what exactly it does.

Secret pictures:
Play the "MAHJONG HOUSE" mode of the "1-PLAYER" game. Select either Maririn or Inajima Oryuu as opponent. Finish match with positive points. At the match results screen enter Up, Down, Left, Right, B. The default message of the opponent will change and the face animation of the character will stop. Now, press any button to advance to the secret pictures of particular girl.

Special secret picture:
There is one more much complicated cheat sequence exists in this game (Up, Down, Left, Right, Up, Up + A, Down, Down + A, Left, Left + A, Right, Right + A, B, A + B, Right, Right + A, Right + A + Select, Left, Left + A, Left + A + Select, Down, Down + A, Down + A + Select, Up, Up + A, Up + A + Select, B, A + B, A + B + Select). It should be entered at the Inajima Oryuu's secret picture. If done right, the breasts area of the girl will be replaced with some patch, but the patch data exactly the same as used in the original picture, so nothing is changes. Most probably, they planned to add some nudity or the original picture were different, but currently there is no point to use this code at all. The only indication that this sequence is working, that the face animation of the girl will stop as well.

Game genie:
FEF?FFC?E6A - Re-enables the Debug features. Most noticeable ones are:
The opponents tiles are now can be seen during the game.
The Tile fetch editor overwriting with more powerful memory viewer/editor. The corersponding cheat at the title screen also disabled, memory view now availableany time by pressing Start.
The tile fetching procedure becomes trivial. The game will just select the tiles in its order in a stack.
Adds a new shortcut for 2-PLAYERS cheat, described above. Instead of entering the Credits screen 255 times, you just need to enter it 4 times at the title screen, then start the 2-PLAYERS mode.
000?00B?C4D - Additionally to the code above, this one adds some debugging display during the game match at the top-right corned of the screen, under the opponent's tiles. There is not clear what it means, but holding Up, then pressing Left or Right during the game sometimes will reveal some changing values there.