Upper House lawmaker Taro Yamamoto, an anti-nuclear activist who was formerly an actor, created a public stir Thursday when he apparently approached Emperor Akihito for political purposes at a garden party hosted by the Imperial Couple in Tokyo.

During the biannual event, where 2,140 celebrities from various fields and policymakers were invited to the Akasaka Imperial Garden, Yamamoto handed a letter to the Emperor, an act that immediately prompted criticism that he might be trying to use the monarch for political purposes, which the Constitution is interpreted to strictly forbid.

Later in the day, Yamamoto reportedly said that he wrote and handed the letter to the Emperor because he wanted him to learn about children exposed to radioactive fallout from the wrecked Fukushima No. 1 nuclear power plant and the horrendous working conditions of those working on the ground.