The use of given names in Japanese is interesting and can be frustrating. First of all, Japanese put the family name first, so the names are generally reversed when making the transition to English.
But the main frustration with given names is that they are used much less than in the West. In Japanese, if you just use someone's given name, it would sound like he or she is a family member or a very close friend. If there are two Suzuki's in the office, they might be distinguished by their given name and possibly by use of only their given names, but this would still be somewhat uncommon.
What is really confusing is when a Japanese uses only his or her given name when doing international business, or worse, he or she chooses a shortened version (such as Tak or Yasu) or even a Western nickname. Generally, that name is of no use when you try to employ it in Japan. If you just ask for someone by his or her given name, you will likely receive a blank stare. Even in the same office, only a minority of people would be able to state the full names of all their coworkers.
Over the past 10 years or so, computer systems have made it necessary to be able to at least pick out the full name of the person you are looking for, but stating full names from memory is another matter.
