A comic book depicting an illustrator's ignorance about a medical symbol worn by people with hidden disabilities has gone viral on Twitter, helping others learn about the tag as well.

The manga, posted by illustrator Puchimei on Sunday, describes his experience on a train when a man standing in front of him was sweating profusely, talking to himself. Puchimei, who was seated, saw a red tag on the man's bag but didn't know what it meant. Before he knew it, the man collapsed.

Afterward, during a search on the internet, Puchimei found the red tag was displaying the Help Mark, a symbol signifying the holder has a hidden disability not obvious by general appearance, such as prosthetic legs.

The comic ends with Puchimei expressing regret and saying that if he had known about the Help Mark, he would have given up his seat earlier and prevented the man's collapse.

The comic strip had been retweeted more than 52,000 times as of Friday.

Created by the Tokyo Metropolitan Government, items bearing the Help Mark have been distributed at Tokyo subways and buses to make Tokyo safer for people with disabilities ahead of the Tokyo Olympics in 2020.

"I wanted to tell people that I felt miserable because I didn't know about the tag," Puchimei said. "I want more people to understand what it means."