I’m a white american, so I’m lacking cultural context

Looks like my suspicions were correct, and the most character development we've gotten for Yor has come about as a result of being introduced to her brother. That's not inherently bad (family says a lot about us, and scenarios like this can open the door to backstory that might otherwise feel forced) except Yuri immediately stands out as an established character. Yor is still sort of a blank being filled in by others, which is especially disappointing in a volume like this that reminds us she is no stranger to hyperviolence. I'm going to keep reading because Endo is a hilarious author and a great artist, but apparently the two kinds of character he can/will write are "man" and "child." This volume also teases that he can write "dog." Still haven't cracked "woman," huh?