This man’s stickers are one of the few visual signs of the Fukushima nuclear disaster.
Known only as "281 Anti-nuke", he has covered Tokyo streets in stencils depicting prime ministers as vampires and children shielding from radioactive rain.
He says that he aims to remind people of the reality of radiation and that revealing his identity will only distract people from his message.
The Fukushima nuclear disaster and its subsequent handling by plant operator Tokyo Electric Power Co (Tepco) prompted wide-spread anti-nuclear sentiment and public protests in Japan.
The street artist says the disaster gave his art meaning.
Many of 281's designs depict children threatened by nuclear power, with the three-pronged atomic symbol taking the place of flower petals, a biscuit, or an inflatable ring.
281 has also branched beyond the nuclear issue to tackle other topics such as the upcoming consumption tax hike or Japan's bid for the 2020 Olympics.
281 says he wants his art to be a signpost for people to be aware of what’s happening—and if it can make people stop and think, then he is happy.
He is a rare specimen in a country where graffiti writers face heavy legal penalties and strong social disapproval, and where netizens have called for his arrest.
Book shop owner Keisuke Narita re-sells some of 281's stickers and says many people still have an interest in what the stickers mean.
Narita says the earthquake and nuclear disaster has made more people willing to look at society and find things they disagree with.
The most politically sensitive stickers have the shortest half-life, lasting less than the average three days it takes for his stickers to be torn down.
Although he sees many Japanese people taking photos and uploading them to blogs and Twitter, 281 admits that most of his fans are not in Japan, where he wants to have the biggest impact.