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Extraction and Repacker Utility for Nitroplus N2System-based games
C Objective-C HTML
Latest commit e24b016 @Wilhansen Merge pull request #3 from rufanov/master
Added support of DRAMAtical Murder re:connect


Nitro+ —
Nitro+ CHiRAL —

Description (from comments)

This is a tool made for Nitro+'s NPA archives which is used by the N2System engine. The engine is used in 6 games total between Nitro+ and Nitro+ CHiRAL. It supports unpacking and repacking even if the format is archived and/or encrypted. There are 3 versions of the NPA archive that is currently known. See npadoc.html (also archived here) for documentation on the NPA format.


For the uninitiated, this is a non-interactive command-line program so this is best run from the command line.

  • General
    • -h — Displays help information and lists Game IDs.
  • Extraction
    • -x (file) — Extract NPA archive
    • -g (id) — Game ID for encryption (if applicable). Defaults to ChaosHead if no encryption is entered
  • Creation
    • -c (folder) (output file) — Create archive
    • -z — Compress files
    • -cg (folder) (output file) (id) — Create encrypted archive using game id.

DO NOT compress a CG folder. There is little change in size by doing so and it messes up the engine. This is a problem with the engine and Nitro+ doesn't compress their CG files because of it.


-x nss.npa — Extract nss.npa into the folder "nss"
-xg nss.npa MuramasaTr — Extract nss.npa into the folder "nss" using the Muramasa Trial encryption
-c nss nss.npa — Create an archive out of the folder "nss"
-cz nss nss.npa — Create a compressed archive out of the folder "nss"
-czg nss nss.npa Lamento — Create a compressed archive of the folder "nss" then use Lamento encryption.

Supported Games

Game IDs in code formatting.

  • Nitro+
    • Chaos;Head ChaosHead
    • Chaos;Head Trial 1 ChaosHeadTr1
    • Chaos;Head Trial 2 ChaosHeadTr2
    • FullMetalDaemon MURAMASA Muramasa
    • FullMetalDaemon MURAMASA Janen Hen MuramasaAD
    • FullMetalDaemon MURAMASA Trial MuramasaTr
    • Guilty Crown Lost Xmas Trailer LostXTrailer
    • Guilty Crown Lost Xmas LostX
    • Kikokugai Kikokugai
    • Kimi to Kajono to Kanojo no Koi Totono
    • Sumaga Sumaga
    • Sumaga 3% Sumaga3P
    • Sumaga Special SumagaSP
    • Demonbane The Best Demonbane
    • Axanael/Axanael Trial Axanael
    • Sonicomi Sonicomi
    • Sonicomi Trial 2 SonicomiTr2
    • Zoku Satsuriku no Django Django
  • Nitro+ CHiRAL
    • Lamento -Beyond the Void- Lamento
    • sweet pool sweetpool
    • DRAMAtical Murder DramaticalMurder
    • DRAMAtical Murder re:connect DramaticalMurderRC


Minagi from the forum for reverse-engineering the npa format and writing the original code.

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