I s the world's second-largest economy, Japan feels it deserves the respect and privilege accorded the club of rich countries.
It certainly mouths money. Japan has been a major (if not the biggest) donor to the WHO, UNAIDS, UNESCO, UNDP, and UNICEF, not to mention the second-largest contributor to the entire U.N. regular budget.
Quid pro quo: Japan periodically campaigns for a permanent seat on the U.N. Security Council. In 2003, foreign ministry representative Takashima Hatsuhisa called Japan's absence from the UNSC "taxation without representation."