Monster Hunter Stories 2: Wings of Ruin may revolve around the idea of adding new Monsties to your stable, but that doesn’t mean you have infinite space. As you play through the game and find more monsters, you will need to unlock additional space to keep them in.
To do this, you will need to play through the game until you meet a strange little cat that gives you access to the Melynx Inc. shop. This will happen while you are still operating out of the first village and doesn’t take too long. The Melynx Inc. shop sells rare but important items and only deals in Bottle Caps.
Bottle Caps can be found in Everdens that are found spread through the game and must be loot from chests. To find an Everden, keep your eyes open for a den with a square stone entrance. The very first Everden you find will be introduced as part of the quest from the mysterious cat.
You can purchase stable expansions called “Stable Blueprints” from the Melynx Inc. shop for Bottle Caps, so check in often and always keep an eye out for Everdens when you are exploring the game. There will be a Melynx Merchant in every town and village you encounter, so they will always be easy to find.