While I would like to provide you with as much information as I can on the topic of Japanese video game edits, there is only so much that I can tell you with my own knowledge.  If you are willing to offer any information (or even pictures) that you have on any video game that hasn't been listed yet, I would gladly accept it, but it must meet a certain criteria before I will post it on the site.  If you are uncertain about what is acceptable, please read both sections of the criteria before asking any questions you may have.

Standards Which Will Be Accepted

Character Changes and Edits
This generally includes replacing one character with a completely different character, sometimes even changing the original character's gender.  Other times, the change involves altering the look and behavior of a character; such as what he or she wears or what type of personality the character has.

Music and Sound Effects Changes
Basically, replacing any part of a game's musical score with another song.  Removing or changing any sound effect with another will also be included.

Content Alteration
This covers a wide range of changes.  From changing how scenery looks, to removing or changing objectionable and offensive content.  Americanized content would also fit in this category.

Script and Dialogue Changes
Includes major differences in what characters say and what happens in the plot. 

Any Other Missing Content
Anything else that hasn't been mentioned above, including parts of a game that have been completely omitted.

Added Content
Sometimes, when a game is translated for the American market, content will be added that was never available in the original Japanese version.  Any game that has meets this situation should be mentioned as well.

Unacceptable Standards

Box Art
First of all, the packaging that holds the game you play has little affect on the game itself.  A majority of the time you'll discover that the Japanese box art will have better quality artwork compared to the American box art.

Character Name Changes
While changing a character's name can be classified as an alteration worth mentioning to some, I feel that it does not qualify as a major change to the actual game play experience.  A character with certain personality traits is still the same character, even if his name is Thomas instead of Takahashi.

Games Missing An American Release
Ugh.  No.  There are just way too many games that have never been brought overseas from Japan to list on this site.  And since they have no American counterpart to compare them with anyway, there is no reason to catalog them on the site.  If you are really curious as to what games weren't brought over on your favorite system, I would suggest checking the system lists on GameFAQs.com for that sort of information.

The English Language
It may not be in Japanese when you play it, but a great game will stay great no matter what language the characters are speaking.  As long as the game's script and dialogue stay faithful to the original version, there is no need to mention it on the website.  And if the quality of English actually spoken is less than perfect, that still doesn't mean it should be listed.

Console Differences
It's usually not uncommon to find differences in a game when it's released on multiple platforms, especially when the game in question is a port of an arcade game.  The differences are usually things like missing and/or alternate content, or more commonly, graphical differences.  While these differences are worth mentioning, I would still prefer to concentrate on games released on the exact same system.

Hidden Code
When a video game is made, developers tend to have a lot of ideas as far as what to put into the game.  When the game is programmed and written in code, parts of the code gets tucked away into the programming to be used when the developers decide to make it an official part of the game.  Often times, some of the code is just left in the program and never seen during actual game play.  Finding the code is an interest to some gamers, however I will only mention content that made the official release.