Nioh 3 Mod Manager

Credits

Huge thanks to eArmada8 for the yumia_fdata_tools ecosystem and Kassent for the Nioh 3 DLL loader + LooseFileLoader plugins.

What is this?

A standalone GUI app for installing and uninstalling Nioh 3 asset mods from archive files.

This manager supports both:

• []Legacy Yumia patch installs

  []LooseFileLoader loose-file installs (preferred)

  It does not manage unrelated DLL gameplay plugins beyond checking required loader/plugin files.

  Key Features

  • []Scans a folder of mod archives (.zip, . 7z, .rar)

    []Auto-detects supported archive structures

    []Supports manifest mods (nioh3modmanifest.json) with per-feature option selection

    []Supports direct loose-file archives, including multi-folder optional component selection

    []Backend-aware install routing (Yumia or LooseFileLoader)

    []Global migration from Yumia-managed installs to LooseFileLoader

    []Installed state tracking and clean uninstall

    Recommended Setup (LooseFileLoader)

    Step 1: Install DLL Loader

    https://www.nexusmods.com/nioh3/mods/49

    Step 2: Install LooseFileLoader

    https://www.nexusmods.com/nioh3/mods/90

    Expected files:

    <Nioh3>\DINPUT8.dll

    <Nioh3>\plugins\LooseFileLoader.dll

    <Nioh3>\plugins\LooseFileLoader.ini

    Step 3: Create a Downloads Folder

    Create any folder for downloaded mod archives (for example `C:\Nioh3_mods`) and place your `.zip`, `. 7z`, and `.rar` files there.

    Step 4: Run Nioh3ModManager.exe

    In Settings, configure:

    • []Mods Directory: your downloads folder

      []Game Package Directory: `<Nioh3>\package`

      If you already have active Yumia-managed installs, use Migrate Yumia Installs once LooseFileLoader prerequisites are ready.

      Legacy Yumia Compatibility

      Legacy Yumia flow is still supported for existing install bases.

      Required file:

      <Nioh3>\package\yumia_mod_insert_into_rdb.exe

      yumia_mod_insert_into_rdb.exe

      Supported Archive Layouts

      • []Legacy Yumia layout with `package/`

        []Legacy Yumia layout with root `.fdata` + `.yumiamod.json`

        []Manifest layout via `nioh3modmanifest.json`

        []Direct loose-file archives (hashed filenames like `0x11A34982.g1t`)

        For direct loose archives:

        • []Root loose files are treated as common files

          []One top-level wrapper folder is treated as one normal install option

          []Multiple top-level loose folders are shown as optional checkbox components

          For Mod Authors

          Use `.zip`, `. 7z`, or `.rar` archives.

          Recommended packaging order:

          • []Best: manifest + loose files

            []Good: direct loose-file archive

            []Compatibility fallback: legacy Yumia payloads

            1) Preferred: Manifest + loose files

            "mod_manager_version": "1. 0",

            "mod_name": "Example Mod",

            "common_files_dir": "common",

            "features": [

            { "name": "Skin", "directory": "skin", "optional": false },

            { "name": "Coverage", "directory": "coverage", "optional": false }

            Example layout:

            nioh3modmanifest.json

            0xA1000001.g1t

            0xA2000002.g1t

            0xA2000003.g1t

            0xA3000004.g1m

            0xA3000005.g1m

            2) Direct loose layout

            Use hashed filenames (for example `0x12345678.g1t`) at archive root or inside top-level option folders.

            3) Legacy Yumia package layout (fallback)

            0xAAAABBBB.fdata

            0xAAAABBBB.yumiamod.json

            Requirements

            • []Windows 10/11 (64-bit)

              []Nioh 3 (Steam)

              []LooseFileLoader prerequisites (recommended) OR Yumia executable (legacy)