Here is the patch for the Japanese Metal Gear ROM. Don't ask me where to get the ROM, if you are a legal user you should dump it yourself. Please read the entire page so that you fully understand what's involved here, thanks.
Disclaimer:
This project is not affiliated with or supported by Konami in any way. "Metal Gear", its logo, as well as the game itself are Trademarks and Copyright of Konami and the logos and art featured here are used without permission. This website makes no claim as to the legality, or lack thereof, of possessing, creating or modifying additional archival copies of the Konami game Metal Gear. It is up to the end-user's due diligence to research and understand the laws of his or her own nation's application in this regard. It is also strongly recommended that the end-user comply with those laws which are applicable, even if it rules out the use of the patch available here.
USE THE PATCH AVAILABLE HERE AT YOUR OWN RISK. The creator of this patch makes no guarantees or warrantee of the effects of this patch. Any damage or loss of any kind resulting from any use of this patch is the user's responsibility, not the creator of the patch.
Be sure to read the readme.txt included in the patch archive (ZIP file) concerning requirements and useage of the patch. If the readme isn't enough to figure out what's going on here, then by all means consult google.com.
Explanation of the Nature of the Game Script:
This is perhaps the most important part. Takamichi Suzukawa and Jon Taylor worked very hard to translate and proof-read the game script from the original Japanese. My job was to figure out how to get all that into the game while still maintaining the specific details, meaning, and context of the messages. So what you get here is a lot of hard work to convey as best as possible the meaning of the original Japanese script.
All 155 messages are present and wherever possible are word-for-word translations. (the UK version was missing 69 of them iirc) Messages that are not word-for-word translations are changed primarily becuase of grammar translation issues or some other similar situation. In addition, Jon's idea was to make sure that the script was compliant with the "Previous Operations" stories in Metal Gear Solid. I've done that so there is perfect symmetry with the information about this game that appears in later games in the series.
To sum up, the original meaning and context has been ardently maintained throughout the script with particular attention paid to major plot issues. For example, some of Dr. Pettrovich's dialog was kept in the original Japanese grammar even though it's quite clumsy for a fluent english reader becuase he speaks at this stage a somewhat broken english (his daughter Elen is the same in some ways). Details like that were maintained as well as was possible and I think this script is pretty good. Anyway, I hope you all enjoy playing the game with a complete script in english finally.
The Patch:
Check Takamichi's Metal Gear Remix Developments Committee page here for his translation of the Japanese manual. The manual includes character bios and other information omitted from english versions.