The company behind the successful Hello Kitty franchise has apologised and ended its commercial tie-up with a Japanese TV drama after Chinese state media and netizens condemned the show’s “deliberate smears” against China.

Sanrio, a Japanese firm whose characters are popular around the world, said in a post on the Chinese social media site Weibo that it had decided to end its association with the TV drama Vivant after concluding that it “contained elements inconsistent with Sanrio’s core values”.

In the second season of the popular spy thriller, produced by the Japanese TBS network, Masato Sakai plays a salaryman who is drawn into a web of international crime and espionage.

The backlash began this week when Chinese state media blasted the portrayal of Chinese agents using “ruthless violence” to torture members of a secret unit of Japan’s self-defence forces, calling it a “deliberate smear” against Beijing.

Chinese media said that some of the torture methods were similar to those Japanese troops used against Chinese civilians during the second world war.

The state-run tabloid Global Times said the acts shown in the episode “bear striking similarities to the torture inflicted on Chinese nationals by invading Japanese troops” during the war, adding that the drama “distorts the truth by attributing these atrocities to modern Chinese characters”.

In the 4 October episode, a Chinese agent is seen cutting off the fingers of the Japanese intelligence officer and stabbing him in the abdomen.

Sanrio said in a statement: “Since its inception, Sanrio has consistently used its characters to convey values such as care and connection, and remains committed to its corporate philosophy of fostering harmony among all people.

“We take the feedback we have received regarding this incident very seriously. Moving forward, we will strengthen our review processes for all future collaborative projects.”

The drama’s first season, set in a fictional central Asian country, avoided controversy, but its latest season is being shown at a time of increasingly fractious relations between Beijing and Tokyo.

Japan’s conservative prime minister, Sanae Takaichi, set off a diplomatic row in November last year when she told MPs that a Chinese attack on Taiwan could trigger the deployment of her country’s self-defence forces if the conflict posed an existential threat to Japan.

Takaichi said earlier this month that she had recorded episodes of Vivant and hoped to watch them over the year-end and new year holidays.

China is a crucial overseas market for Sanrio, whose cast of characters includes My Melody and Cinnamoroll – both featured in Vivant-themed merchandise.

The Tokyo-based company racked up 781m yuan ($117m) in revenue from the Chinese market in the first half of this year, according to Chinese media, up more than 40% from the same period last year.

The backlash against Sanrio comes days after the French international footballer Kylian Mbappé was dropped by several Chinese brands after he jokingly referred to Mao Zedong as a “dictator”. The Real Madrid forward, who is nicknamed the “dictator” for his influence on the game, later apologised for his “ill-judged” remarks.