Oh... so that's the pun with Yōmu.
So, we all know that she's half-human, half-ghost. In Japanese, this is "hannin hanrei" (半人半霊).
Now, there is a phrase in Japanese – "zenshin zenrei" (全身全霊) literally full body, full soul – which means to do one's best.
The idea being that "身" can also mean person just like "人"
