Japan's Shoei USA Inc., a helmet manufacturer, paid $37.75 million in the leasehold purchase of the iconic Bank of Hawaii Waikiki Center, according to public records. Up until now, the sales price of the 153,059-square-foot, nine-story building at 2155 Kalakaua Ave. - which includes a mix of office and retail tenants, including Bank of Hawaii, Starwood Hotels & Resorts, JTB Hawaii and 7-Eleven and soon-to-be Waikiki's first Longs Drugs store - was unknown. The previous owners, Honolulu-based…