On December 7, 2019, Shoji Gatoh posted controversial remarks to his Twitter feed in response to an NHK report about teenage environmental activist Greta Thundberg's appearance at COP25, a climate change conference in Spain. The comments read, "I hate that kid. If I was the ruler of the world, I would steal everything from her, knock her into the depths of despair and ridicule her. On top of that, I'd feed her a delicious, piping hot steak and watch her shed bitter tears. I’d love to see that." Gatoh later removed his tweet in response to public backlash and apologized for writing it.1Убийца Ити: Приквел

Tetsuro Kasahara, who illustrated the manga Full Metal Panic! Zero, tweeted in response, "I did the art for a manga created by this person, but I don't agree with his remarks. I will no longer do any promotion for Full Metal Panic! Zero, nor draw any continuation. I will also donate any profits from the manga to environmental groups." Following the apology of Gatoh, he redacted this statement