Possible Clues:

• Japan’s former capital
• 1997 environmental treaty site
• Home of many Shinto shrines (... + first 2)
• Exotic Tokyo, Japanese city
• Japanese city — Tokyo (anag)
• Japanese capital from 794-1868
• Japanese capital before 1868
• City in central Japan
• Japanese city of treaty on climate change
• Honshu location: Tokyo perhaps?