Confluence wildcard search(* and ?) are different?

My Confluence’s data use Japanese, so I set the index language to Japanese.

But When I search the data by using (*) and (?) , the result is different.

・The data in a page :


・search word:

生産*部 -> No result

生産?部 -> Hit the page

I know that the Lucene has said below:

Lucene supports single and multiple character wildcard searches within single terms (not within phrase queries).

To perform a single character wildcard search use the “?” symbol.

To perform a multiple character wildcard search use the “*” symbol.

But why Result are different between “?” and “*” ?

Does Confluence has some special actions?

My Confluence’s version is 6.6.1