Skip to content
Extraction and Repacker Utility for Nitroplus N2System-based games
C Objective-C HTML
Branch: master
Clone or download
Wilhansen Merge pull request #3 from rufanov/master
Added support of DRAMAtical Murder re:connect
Latest commit e24b016 Jul 2, 2015
Type Name Latest commit message Commit time
Failed to load latest commit information.
vc10 Bumped version Mar 3, 2012
.gitignore Add VC10 solution files Feb 25, 2012
nipa.c Added support of DRAMAtical Murder re:connect Jun 30, 2015
nipa.h Added support of DRAMAtical Murder re:connect Jun 30, 2015


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.

You can’t perform that action at this time.