On December 8, 2019, Gatô posted a disrespectful Twitter against teenager environmental activist
Greta Thunberg, on occasion of her appearance on COP25. Gatô stated in Japanese "I hate this child", expressing his desire to ridicule her with cruel words. Due to backlash from the public and from manga artist
Tetsuro Kasahara, Gatô latter apologized and deleted the nasty Tweet.
