noun
sense of duty; sense of obligation
Refers to an internal feeling that one must do something because it is one's duty or responsibility.
彼は強い義務感から、毎日ボランティアを続けている。
Out of a strong sense of duty, he continues volunteering every day.
義務感だけで仕事をすると、疲れてしまう。
If you work only from a sense of obligation, you'll get tired.
使命感 is a sense of mission or calling, often with a positive, proactive nuance, whereas 義務感 can feel more like a burden or obligation.
Compound of 義務 (duty, obligation) and 感 (feeling, sense).