Does putting asterisks in, like ははち*め on this site do what you're hoping for? It works for me. Asterisks are wild cards in most search tools.
Hmm, I put asterisks in the same spots as you put O's above, but it doesn't display properly on the forum.
Question marks work: a jisho search for は?はち??め will do almost exactly what you want. (Asterisks match one or more characters, whereas question marks match just the one.)
The caveat is that the ? will stand in for any character, not a mora… so there are some bogus results where the ? gets filled in by a kanji whose reading is longer than one mora. But you can filter those out manually.
@Leebo: That's probably because of Markdown. https://daringfireball.net/projects/markdown/basics
* are used to emphasize text.
I've used asterisks before (not reaaally working for me either) but question marks do their job really well. Thank you so much for your replies!
Using the asterisks brings up the word you were asking about, no? Is there some other example where it doesn't work?
For example: if you type かづめ, a result would be かんづめ. It includes words where something can be at the place of the asterisks, but doesn't have to.
か * づめ *
Japanese Word Gap Solver
This doesn't have to do anything with tze word, but is there a tool so you can insert the gaps in Japanese words? For example:
はOはちOOめ
And the tool would give answers which syllables can fit into that, for this one はらはちぶんめ for example.