Henry is super nervous when he first meets Keiko's parents, but over time he gets to know them and finds that he's comfortable with them—in some ways, more so than he is with his own parents. They accept Henry wholeheartedly for who he is, after all, which is a refreshing prospect:
"Henry, this isn't about us. I mean, it is, but they don't define you by the button you wear. They define you by what you do, by what your actions say about you. And coming here, despite your parents, says a lot to them—and me. And they're Americans first. They don't see you as the enemy. They see you as a person." (41.9)
Because of their acceptance and kindness, Keiko is an open-minded and strong girl, and she's not going to let discrimination and turmoil stop her from succeeding in life. They've taught her how to be resilient and positive, and it shows.