Name: I drink Sorrel Coffee to reboot reality, but I'm being hunted by Monster Girls and armed agents - Artbook and Wallpapers DLC (Steam)
Brand: TopHouse Publishing
SKU: KT-A0434C4135
Price: 1.31 EUR
Availability: InStock

Unlock the mysteries of creating the visual world of “Sorrel Coffee” with this unique art collection set! This DLC includes: A complete artbook, containing concepts, character sketches, locations and final versions of images A collection of exclusive wallpapers for your device To access it, go to the game's installation folder, open the "Artbook and Wallpapers" directory, and enjoy!

Redeem on Steam

You need a Steam account and the Steam app.

Step 1: Open Steam and sign in.
Step 2: Open the Games menu, then choose Activate a Product on Steam…
Step 3: Enter the key and follow the prompts.
Step 4: The game appears in your Library.

Steam's redeem page Full guide for Steam

Activation notes from the publisher

Go to: http://store.steampowered.com/ and download STEAM client Click "Install Steam" (from the upper right corner) Install and start application, login with your Account name and Password (create one if you don't have). Please follow these instructions to activate a new retail purchase on Steam: Launch Steam and log into your Steam account. Click the Games Menu. Choose Activate a Product on Steam... Follow the onscreen instructions to complete the process. After successful code verification go to the "LIBRARY" tab and start downloading.