This is the 4778th most frequent Japanese word.
正男
"正男" is a Japanese male given name meaning "righteous man" or "correct man."
In this sentence, '正男' is used as a proper noun, referring to a person's name, and 'さん' is a respectful title.
正男さんは明日会議に出席します。
Mr. Masao will attend the meeting tomorrow.
Here, '正男' is treated as a subject for discussion, referring to a specific name or term.
正男という名前はとても珍しいです。
The name Masao is very uncommon.
In this instance, '正男' refers to the author of the novel, specifically attributing the creation to a person named Masao.