Exuberant Ctags with Japanese language support.

Exuberant Ctags generates an index (or tag) file of source language
objects in source files that allows these items to be quickly and
easily located by a text editor or other utility.

Alternatively, it can generate a cross reference file which lists,
in human-readable form, information about the various objects found
in a set of source code files.

Supported languages include: Assembler, ASP, AWK, BETA, C, C++, C#,
COBOL, Eiffel, Fortran, HTML, Java, Javascript, Lisp, Lua, Make,
Pascal, Perl, PHP, PL/SQL, Python, REXX, Ruby, S-Lang, Scheme, Shell
(Bourne/Korn/Z), Standard ML, Tcl, Vera, Verilog, Vim and Yacc.