The Toxic Kumori in Monster Hunter Rise is a rare item that you can get only from a specific place in the game. It can be used to upgrade weapons and armor and quite essential if you are on a quest to get the best weapons. If you are unfamiliar with the Argosy, they are merchants that trade in all types of items. Some of the items in the game can only be obtained from them, but you have to unlock trading with them first. Here is how to get Toxic Kumori in Monster Hunter Rise (MH Rise).
Monster Hunter Rise Toxic Kumori Location Guide
To get Toxic Kumori in Monster Hunter Rise (MHR), you will have to trade with the Argosy. But, before you start trading, you need to unlock the Argosy trade ship. The trade ship can be unlocked by progressing in the game to the 2 Star Village Quests. Once you have reached this level in the game, go to the Argosy dock near Buddy Scout center and talk to Rondine.
To farm Toxic Kumori in Monster Hunter Rise, first, hire a buddy, then go to the Argosy dock to talk to Rondine and set up a trade frame with the buddy. Go to Order Item and then Trade Requests. Now, you can send your buddy out to various markets. When your buddy returns with items, the game will notify you. One of these items can be the Monster Hunter Rise Toxic Kumori. There is no other way in the game to get the Dreamshell.
The best market that is known to provide the Toxic Kumori is the Mushyroom Market, Icebarb Bazaar, and Sungnug Fruitfair. So, assign your buddy to that market, and with some luck, you can get the item you want.