This is the 8688th most frequent Japanese word.
日記
Diary.
Here, '日記' is used more as a specific object, namely the actual diary that contains memories.
この日記には、子供の頃の思い出がたくさん詰まっています。
This diary is filled with many childhood memories.
In this sentence, '日記' refers to a physical or conceptual diary, emphasizing the act of maintaining daily entries.
私は毎日、日記を書くようにしています。
I try to write in my diary every day.
In this sentence, '日記' refers to the general concept or activity of diary-writing.