noun
statement of purpose; application essay
A formal document submitted with university or job applications in Japan, explaining the applicant's motivations, goals, and reasons for applying.
大学に出願する際には、志望理由書を提出しなければならない。
When applying to a university, you must submit a statement of purpose.
彼女は志望理由書に、なぜその会社で働きたいかを詳しく書いた。
She wrote in detail in her application essay why she wants to work at that company.
Compound of 志望 (aspiration, desire to apply) + 理由 (reason) + 書 (document).