Asako Yuzuki, left, signing Butter at Waterstones Piccadilly

SOME months ago you couldn’t hop on a tube without seeing some passenger clutching a yellow book featuring a cow on its cover.

Asako Yuzuki’s Butter, about a journalist looking into the case of a woman accused of murdering her former lovers, became a smash hit among young people.

In the story, the lead character faces criticism for putting on weight while the journalist revels in the pleasures of eating indulgently at fancy restaurants and also – in one bizarre scene – her own scab.

At a talk in Piccadilly Waterstones, Asako said she was surprised by the critical reaction in this country that saw the novel read as a damning indictment of Japanese beauty standards and pervasive misogyny.

But she said: “I wanted to focus on how Japanese people have internalised that trend of media reporting.

“It wasn’t my intention to expose the misogynistic element in Japan, I was merely writing about daily life in Japan. This is what most women go through.

“My intention was to see what one person goes through in their daily life, and what is an adequate amount of diet culture.

“It was interesting that it was regarded as an exposé.”