In April 2011, Park performed with Japanese duo Mihimaru GT at a UN Charity Concert in Yokohama, Japan to aid victims of the 2011 Tōhoku earthquake and tsunami. He volunteered and performed during the United Nations charity event: "Friend's Whistle! Act For Tomorrow!". Along with the members of Choshinsei(Supernova), he also stood outside the event hall at Pacifica Yokohama to collect monetary donations. Moreover, he performed on April 28 to encourage people to donate.