The skies above the Hiroshima Peace Memorial were perfectly clear last Tuesday morning — until a small plane appeared and started writing in smoke a Japanese word that could be translated as "Bang!"

In an article the next day, the local Chugoku Shimbun reported it was flooded with phone calls from citizens who had seen the skywriting, which was obviously designed to remind them of the atomic bombing of the city 63 years ago. Most callers, the newspaper reported, expressed "displeasure."

It turns out that the stunt was the latest project by artist group Chim ↑ Pom, whose shock tactics The Japan Times covered this summer. They were filming the word as it floated in the sky above the memorial that they planned to submit for a solo show at Hiroshima City Museum of Contemporary Art next month.