Trim the roots of the scallions and cut them in half lengthwise.

Clean the squid by cutting open the body, removing the innards and cartilage. Separate the tentacles, remove the eyes and beak, and cut into bite-sized pieces.

Boil water in a pot, add a pinch of salt, and blanch the scallions for 1 minute. Transfer to cold water and drain.

In the same boiling water, cook the squid until it changes color. Transfer to cold water and pat dry.

Roll the scallions on a cutting board with chopsticks to remove the slimy texture, then cut into 4cm pieces.

In a small pot, combine white miso, vinegar, and sugar. Heat over low heat while stirring constantly until it starts to bubble. Remove from heat and let it cool.