Hirooka's activism gained international attention in 2019 when she joined the global climate strike movement, inspired by Swedish activist Greta Thunberg. She began organizing protests and rallies in Japan, calling for the government to take more decisive action on climate change. Her message resonated with many young people in Japan, who were increasingly concerned about the country's slow response to the climate crisis.

Growing up in Kyoto, Hirooka was always fascinated by science and the natural world. She developed a strong interest in environmental issues, particularly climate change, which she learned about in school. Her concern about the impact of human activities on the planet only deepened as she grew older. In 2018, at the age of 20, Hirooka decided to take a gap year from her studies to focus on climate activism.

Mirai Hirooka is a Japanese climate activist who has been making headlines globally for her passionate advocacy on environmental issues. Born on November 7, 1998, in Kyoto, Japan, Hirooka has become a prominent voice in the fight against climate change, inspiring a new generation of young people to take action.