Romanization is done here using using a 7bit version of modified ↗Hepburn romanization. While Unicode gives us the ability to enter macrons (eg Tenchi Muyō), many Unicode aware browsers still can't display them. Additionally, they're not easy to type on any keyboard. Some use the circumflex (eg Tenchi Muyô) which is available on many European keyboard layouts and a part of the Kunrei-shiki romanization scheme. This is still difficult to type for those of using English keyboards. Also, in the fan community (in at least the US) the 7bit form has traditionally been used (this no doubt dates back to Usenet in the late '80s).
There is, in fact, only one difference from Modified Hepburn: Kana are expressed with their roman equivalents even when they do not represent a new sylable. That is:
- おお is written as oo and おう is written as ou, etc.
- Wikipedia's ↗romanization of Japanese article.