To install the DLC for the steam version, follow these steps:
1. First, open the Steam version's folder. To find it via Steam, do the following:
- Right click on NEKO-NIN exHeart. Click on Properties
- From there, click on Local Files
- Click Browse Local Files. You should see a folder that looks like this:
2. Open up the zip folder (make sure you have redownloaded this from denpasoft) and copy all files from this zip into the main game.
3. Copy the files from step 2 into the game folder from step 1.
4. Enjoy the game!