This is indeed a commonly used chengyu with similar meaning. But I perceive "初志" as having a connotation of "original" or "initial" intentions, whereas "矢志" sim

This is indeed a commonly used chengyu with similar meaning. But I perceive "初志" as having a connotation of "original" or "initial" intentions, whereas "矢志" simply implies determined wishes or promises without emphasizing the "initial" aspect. While I'm not an expert in Japanese, my understanding is based on the Chinese perspective, and the actual meaning of "初志" in Japanese might differ.