Please enjoy the Karashi Sumisoae as soon as possible, otherwise it will become mushy and the color of the wakegi will be ruined from the acid of the vinegar.
Wakegi doesn’t have a pungent smell like spring onions and is tender, so it’s perfect for this kind of dish. Even if the tips of the leaves are removed, cooking the wakegi in boiling water may cause them to burst wide open so please be careful while cooking.
White miso is low in salt so reduce the amount of miso if you are using regular miso.