As long as Kotake is in her shop, the shop works in the following way after Kotake talks to you automatically until the next time you leave the shop:
- You can always buy a red potion or green potion but can't buy a blue potion until you give Kotake a magical mushroom. There are magical mushrooms lying around the Woods of Mystery that are only visible when you're wearing the Mask of Scents. Furthermore, you can only capture a magical mushroom in a bottle when you're wearing the Mask of Scents, even if you swing the bottle exactly where it is. Every time you select "Speak to the Hag," she will ask you for a magical mushroom. If you've never given her a magical mushroom before, the blue potion will be unavailable and she will give you nothing when you give her one. If you have given her one before, the blue potion will be available only if you reenetered the shop since you gave her the first one and when you try to buy it, it will be free only if it's the first time you try to buy it since you first entered the shop after giving her the magical mushroom, and she will give you 20 rupees if you give her another magical mushroom. You can also do bottle duplication the same way as the Curiosity Shop method every time she offers you money for a magical mushroom.