Interface shortcoming. The drop down list limits itself to the first n hits, and doesn't allow to scroll to the ones below. The same happens with "go", which was reported ages ago.

Here's one workaround: Select one item in the list, press "Enter", then in the address bar replace the value of the search parameter with the term you want. Or enter the address directly:

http://kanji.koohii.com/study/index.php?search=me

Yes, but what he's saying is that once you click on a keyword and it's displayed on the right, you'll notice that the address bar at the top of the page is displaying "http://kanji.koohii.com/study/index.php?search=", followed by the keyword you're currently looking at.  So, just replace that keyword with the one you want to go to, and it should take you to the right page.

Glad that's sorted out.

Suggestion for Fabrice: You could take a cue from Excel a.o. and make the drop down list disappear whenever the user hits the Esc key. That would provide one way for users to enter short keywords that are otherwise unreachable.