TOKYO, June 13 : Japanese investors were willing to subscribe to more than 1 trillion yen ($6.2 billion) of shares in SpaceX's record-breaking IPO, two sources familiar with the offering said. The majority of the demand came from retail investors, added the sources, who declined to be identified as they were not authorised to speak publicly about the IPO. Japanese investors ultimately received $2.2 billion worth of shares, a filing showed on Friday. The oversubscription rate was roughly in line