A friend of mine noticed that Japan's stamps are rarely cutesy compared to other forms of media, and I recall my father (who is Japanese) regarding the postal service in high esteem. What's the history behind the mail in Japan?
During the Edo period, the hikyaku (it used a relay system via horses and foot) were the mail carriers. By the middle of the Edo period there were express services that promised to carry the letters between Edo and Osaka within 6 days (roughly 300 miles). Normal services took about 10 days. The cheapest rate took around 30 days (with no guarantee of time). The super express promised to carry letters within 4 days but this one was really expensive.
There were official hikyaku ran by the shogunate and some by major domains. There were also private hikyaku.
Nippon Express is the corporate descendant of the Edo hikyaku guild which renamed itself the Rikuun moto kaisha (Land carrier original company) in 1872.