The Mozc extended dictionary system and user dictionary solved the
challenges of "legal affairs, operations, and quality."

The vocabulary (approximately 1.02 million words) from "UniDic" the
highest-quality corpus compiled by the National Institute for Japanese
Language and Linguistics, has been optimized for Mozc's algorithms,
resulting in approximately 354,000 practical basic forms.

The most distinctive feature of this project is that it requires no
complex build chains such as C++ compilers or Bazel. It can be
imported directly from the GUI's Dictionary Tool.

Mozc's user dictionaries have a limit of 100,000 words per file so
they are automatically split into manageable sizes.