First, follow the guide to confirm certain things

1. Did you put the costume on a mannequin?
- You are able to put clothes on mannequins in Play Together.
- Check if the mannequin you’ve dressed is installed in another house. (Furniture is bound to the house it is installed in.)

2. Furniture is bound to the house that you install it in and you must retrieve the furniture before placing it in a new house.
- Change back to previous house.
- Select all installed furniture from [Furniture editing mode > Installed Furniture] and retrieve installed furniture.
- Place the retrieved furniture in the new house.
* Wallpapers and Floor Papers cannot be retrieved. (If not used previously, they can be used at all houses.)

3. Did you recycle the costume along with other items you recycled?