There are some tesujis that are important (I think) but don't seem to have commonly known names that can be found at NamelessTesuji. Some of them are actually not nameless - just that the English name is not known to most people. :-)
Hey, a real reason to learn Japanese (instead of wanting to read the text in the HikaruHandheldGame)!
If you don't know what a Japanese Go term means, you could make a reasonable guess (i.e. Niken Hiraki = two space extension because ni = two, ken = space (back-formation from ikken) and hiraki = extension because the page says so) -- JanDeWit