There is a link to the full text in CiNii Dissertations but the paper does not seem to be available on the Internet. How can the full text be obtained?

If "NDL Digital Collection (NDL premises only)" is displayed

The paper can be accessed only from terminals on the premises of the National Diet Library.
If "NDL Digital Collection (Distributed only to libraries)" is displayed
1. Persons affiliated with a university or other such institution
  Inquire with the library or media center, etc. of your institution.
2. Persons not affiliated with a university or other such institution
  Check with a local public library, which may have terminals from which the paper can be accessed.