Koikatsu & Koikatsu Sunshine
Free. Made by someone who got fed up with the whole scenes and cards folder mess.
Local app. Portable ZIP. No account. No telemetry.
Current release
Windows SmartScreen may warn on first launch. No malware.
* Card feature is not available yet, sorry. m(_ _)m
Main window: scene grid, search, tags, authors and
inspector
What is it
If you have used KK or KKS for a while, your collection is probably a mess: nested folders, vague names, duplicate downloads, repeated saves and a lot of files you don't even remember anymore.
KK Library is a local desktop app that helps scan those folders, show what is inside, find duplicate or similar content, fix tags and author names and reorganize files easily.
| Price | Free. Forever |
|---|---|
| Supports | Koikatsu and Koikatsu Sunshine (but not required) |
| OS | Windows 10 (x64) and Windows 11 (x64) |
| Size | ~100 MB (~44Mb zipped) |
| Free space | At least 150 MB for the app itself |
| Installation | Not required. Portable ZIP |
| Network | Not required (unless you want to) |
| Languages | English and Japanese |
Find scenes across your folders
Browse, search and inspect scenes without opening the game.
Main library view and folder scanning result
Find duplicates and similar scenes
This is likely what you have been looking for. Find and get rid of all those duplicated scenes or variants without losing what is important to you.
Exact duplicates and similar-scene review
Tags, ratings, favorites and all that
Add the information your scenes usually do not have, so you don't have to open them every time to check.
Tags, ratings, favorites and author cleanup
More tools
Sort scenes into a cleaner folder layout. You see the move plan first, then apply it.
Send a scene straight to CharaStudio, without digging through the in-game loader.
Mark scenes Safe or R-18 and blur previews.
Panic button (esc) hides everything and minimize.
Tags, ratings and authors are tied to the scene itself, so they survive moves and re-packs.
Select a pile of scenes and tag, rate, or fix the author on all of them at once.
Built for oversized, messy libraries: thousands of scenes stay quick to browse and search.
F.A.Q
It's safe, it's just not code-signed. A signing certificate costs money every year and this is a free side project, so Windows SmartScreen flags it the same way it flags any small unsigned app. Choose "More info → Run anyway" to start it. If you want to be sure first, check your download against the SHA-256 on this page. Since the app is portable and offline, you can run it from a throwaway folder or a VM and watch what it does.
It does not touch your mods or saves. The one thing it adds to your Koikatsu folder is a small bridge plugin (in BepInEx/plugins), installed when you connect your game so "Open in CharaStudio" can work: it sits alongside your other plugins and changes nothing else. If you never connect the game, it does not write there at all.
No. It can scan and manage scene files on a PC that does not have the game at all. You only need Koikatsu installed for the optional "Open in CharaStudio" button.
Scanning only reads, it never changes your originals. The only changes are ones you trigger yourself: deleting moves scenes to a Trash you can restore and reorganizing shows you the whole plan first and can be undone. If something looks wrong, it is recoverable.
No account, no telemetry and nothing about your files leaves your PC. The one exception is an optional update check: on launch it can fetch a tiny file to compare version numbers (nothing about you or your library is sent) and you can turn it off in Settings.
When a newer version is out, the app shows a small note with a download link. You grab the new ZIP and replace your old folder (Your settings and data stay where they are). Nothing installs or updates itself in the background.
It is portable, so there is nothing to uninstall: delete the folder and it is gone, with no leftovers. To carry your work across, export your tags, ratings and authors to a file and import it on the other machine (or after a re-pack).
Full Feature List
This is the long-form reference list: what KK Library can do today, where to find it and when it showed up.
Scenes are supported now. Card and outfit support are planned, not available yet. "Early beta" means the feature shipped before this site started tracking every addition in detail.
| Feature | What it does | Where | Available since |
|---|---|---|---|
| Scene folder scan | Scan one or more folders and build one searchable scene library. | Main window, Add Library, Manage Libraries | Early beta |
| Scene metadata reading | Read preview, game, version, cast count, map, date and mod dependency list without opening the game. | Grid cards, Inspector, Details | Early beta |
| Animated scene detection | Mark scenes that use Timeline animation and let you filter for them. | Grid badges, sort bar | beta.3 |
| Modded / vanilla readout | Show whether a scene uses mods and list the dependency IDs it needs. | Inspector, Details | beta.3 |
| Background indexing | Make the library browsable quickly while indexing continues in the background. | Main window during Sync | beta.3 |
| Pause and resume indexing | Pause a long scan or update-time fill pass and continue later without starting over. | Main window progress strip | beta.4 |
| Feature | What it does | Where | Available since |
|---|---|---|---|
| Thumbnail library view | Browse scenes in a grid built for large libraries. | Main window | Early beta |
| Sort and quick filters | Sort by date or name and quickly narrow to animated scenes. | Toolbar / sort bar | beta.3 |
| Faceted navigation | Browse by library scope, author, tags, favorites, duplicates and Trash. | Left sidebar | beta.3 |
| Unified search bar | Search by text and combine it with author, tag and "similar to" chips. | Top search bar | beta.3 |
| Details popups from review tools | Open a scene details view from review tools without leaving the current workflow. | Duplicate / similar review dialogs | beta.3 |
| Feature | What it does | Where | Available since |
|---|---|---|---|
| Tags | Add structured tags to single scenes or selections in bulk. | Inspector, bulk panel, Tags sidebar | Early beta |
| Ratings and NSFW blur | Mark scenes Safe / R-18 / Unrated and blur R-18 previews by default. | Inspector, bulk panel, main window | Early beta |
| Favorites | Mark scenes for quick return and browse them from a dedicated scope. | Grid, Inspector, Favorites scope | beta.3 |
| Author management | Assign, confirm, rename, merge, or remove authors, with "? Unknown" supported explicitly. | Inspector, Authors sidebar, Manage Authors | beta.3 |
| Smarter author detection | Detect likely authors from folder layout instead of just taking the top folder name. | During Sync, Manage Libraries | beta.4 |
| Known creator recognition | Recognize many creator folders automatically and unify common aliases to one name. | During Sync, Settings | beta.4 |
| Per-library author rules | Tune author detection separately for each source library and preview the result live. | Manage Libraries | beta.4 |
| Feature | What it does | Where | Available since |
|---|---|---|---|
| Exact duplicate review | Group byte-identical files and let you choose which copy to keep. | Tools / Review Duplicates | beta.3 |
| Recommended keeper hint | Suggest which duplicate copy is most worth keeping. | Review Duplicates | beta.3 |
| Duplicate path-pattern filter |
Narrow duplicate review to groups that have a copy under
matching folders, using full-path wildcards like
*/Downloads/*.
|
Review Duplicates | beta.4 |
| Similar-scene review | Find scenes that look or behave like variations of each other, not just exact copies. | Tools / Similar Scenes, Inspector → Find similar | beta.3 |
| Similar-scene threshold | Adjust how strict the similar-scene review should be. | Similar Scenes review | beta.3 |
| Feature | What it does | Where | Available since |
|---|---|---|---|
| Trash bin | Move scenes to Trash first, then restore or empty it later. | Inspector, Trash scope | beta.3 |
| Empty Trash with progress | Clear Trash in the background with visible progress and cancel support. | Trash scope | beta.4 |
| Arrange Files | Reorganize scenes into a cleaner folder structure with a dry-run preview first. | Tools / Arrange Files | beta.3 |
| Undo last Arrange | Reverse the most recent Arrange run. | Arrange Files | beta.3 |
| Inline file rename | Rename a scene file in place without losing its tags, rating, favorites, or author data. | Inspector | beta.4 |
| Export / import my data | Back up and restore your tags, ratings, favorites and author work. | File / Export, File / Import | beta.3 |
| Feature | What it does | Where | Available since |
|---|---|---|---|
| Open in CharaStudio | Send a selected scene straight into CharaStudio using the bundled bridge. | Inspector | beta.3 |
| Bridge setup | Configure the Koikatsu install folder and install or update the bridge from the app. | Settings, first-run setup | beta.3 |
| First-run setup wizard | Help new users connect Koikatsu and add their first scene folder. | First launch | beta.3 |
| Language switch | Use the app in English or Japanese. | Settings | beta.3 |
| Cache and scan settings | Control thumbnail cache, ignore rules and author-detection vocabulary. | Settings | beta.4 |
