It is unusual for teachers to encourage their students to watch cartoons but a Japanese anime series set inside the human body has become a regular part of science homework for some children in China. The series, Cells at Work ! , is not only popular with biology teachers. Since its debut in July it has gained more than 56 million views on Bilibili, China’s version of Netflix for anime, to become the most watched show in the form this season. Viewing figures for Cells at Work! are about 27 per cent higher than its nearest rival, the sequel to popular fantasy anime Overlord . The show’s heroes and villains are the tiny cells that make up the human body. Each episode features their struggles and relationships as they carry out their vital work to maintain the body’s health. Biology teachers at the High School Affiliated to Southwest University were so impressed with the accuracy of the series they assigned it as homework for their students. “It helps students understand and remember the biology information they have learned in school, in a much more entertaining way,” a faculty teacher, surnamed Yang, said. Cells at Work ! is also a trending topic on Chinese social media, with fans posting pictures from the show and urging others to watch. Chinese anime rising as country’s tech giants engage in cartoon arms race to develop or buy Chinese characters The show’s heroine is a hardworking but reckless red blood cell whose job is delivering oxygen. A high school student surnamed Chen, from the eastern province of Zhejiang, said she watched the show because her biology teacher had recommended it. “I love how it illustrates cells in the form of human beings,” said Chen. “And the white blood cell is so cool.” In the first episode, a group of white blood cells, called neutrophils, come to the rescue of the oxygen carriers when a purple multi-limbed monster invades the lung area. The villain is a bacteria called Streptococcus pneumoniae which can cause pneumonia if it is not killed by the cell police – the neutrophils, which are the first cell types to travel to the site of an infection. It is not easy for anime shows and games to win the hearts of teachers and parents, who usually regard them as a distraction from studies. Six episodes of the 13-part series have aired so far in China on Bilibili, which last month was told by the Chinese government to filter its content and promote “positive energy”. Video sharing site Bilibili removed from app stores amid Beijing’s content ‘clean up’ In response, the website, which was listed on the US Nasdaq in March, has said it would hire more content moderators in addition to its 36,000-member reviewing team. “Biology teachers should play Cells at Work! before they start lecturing, and let students point out what kind of knowledge they need to learn from the show,” one internet user commented on Weibo, China’s Twitter-like microblogging platform. “I would definitely be better at biology if I had watched this anime in high school,” another one said. The show has been adapted from a manga written and illustrated by Akane Shimizu which has been published in the Japanese magazine Monthly Shonen Sirius since 2015.