This came out of the vegetarian meals eaten during training at Koyasan, the mountain temple complex founded by Kukai around twelve hundred years ago. Sesame itself is said to have been brought back by him from Tang China and planted here.

The reasoning behind it is nutritional and completely explicit. A diet with no meat and no fish runs short of protein. Sesame has protein. So sesame was eaten, and this dish is the form worked out to get as much of it into a monk as possible.

The method is fussy. The seeds are not roasted. They are hulled raw, then ground with water from the mountain and kudzu starch from Yoshino, worked in a suribachi until smooth, and cooked until it sets. What results is dense, cool, faintly bitter, and holds together like a firm custard while dissolving completely on the tongue. There is a theory that it descends from a preparation called ma-dofu recorded in a 1697 vegetarian cookbook.

In the Showa era it became known as a souvenir from Koyasan, and it is now a standard item on any respectable Japanese menu. A dish invented to fill a gap in a monk's nutrition has ended up as a small elegant course served to people who are not going without anything.