He'd agreed to an early retirement deal at Boeing Field and now had all the time in the world, and no one to share the hours with. No one with whom to walk down to the Mon Hei bakery for yuet beng, carrot mooncakes, on cool autumn evenings. (1.8)
Henry's retirement is supposed to be a fun and relaxing time, but that's gone out the window with Ethel's death. Now he doesn't have anyone to share his free time with, and it's awfully lonesome to wander the streets by himself.
Henry wasn't sure which was more frustrating, the nonstop taunting in the school cafeteria or the awkward silence in the little Canton Alley apartment he shared with his parents. (4.1)
Life is hard for little Henry, who feels completely isolated both at school—where he's bullied for being the only Asian kid—and at home. His parents won't even talk to him because they don't speak the same language.
"That's fine. Be who you are," she said, turning away, a look of disappointment in her eyes. "But I'm an American." (12.101)
Keiko thinks Henry understands her plight because he's Asian, too, but when the Japanese Americans in Seattle are being bullied and evacuated, she feels alone even when she's with him since he doesn't have to go through the same degree of suffering and unfair treatment.
The lack of meaningful communication between father and son was based on a lifetime of isolation. Henry had been an only child, without siblings around to talk to, to share things with constantly. And Marty was the same. Whatever stumbling methods of communication Henry has used with his own father seemed to have been passed down to Marty. (13.2)
Henry and Marty have had similar upbringings and both have a difficult time sharing and talking openly with each other. That's why they feel so isolated and lonely even when they're trying to spend time together.
Henry lingered at the edge of the boarding area, waving good-bye as they pulled away from the station, disappearing from sight. He wiped warm tears from his cheeks, his sadness diluted by the sea of families waiting for the next train. Hundreds of families. Thousands. (26.88)
After Keiko and her family are evacuated, Henry feels so alone—not just because his best friend has left but because the entirety of Japantown is now empty. The whole vibrant community has been removed.
But from that moment on, he began to feel like a ghost in the little brick apartment he shared with his parents. They didn't speak to him; in fact, they barely acknowledged his presence. They'd speak to each other as if he weren't there, and when they looked his way, they'd each pretend to look right through him. (36.1)
Henry's home life isn't going so well ever since his father disowned him. His parents act as though he doesn't exist and ignore everything he says; they're determined to make him feel as alienated as possible.
By the time Saturday rolled around, Henry longed to talk to someone—anyone. He had tried to catch Sheldon during the week, but there was never any time before school. After school, Sheldon was always performing at the Black Elks Club, which had just reopened. (36.10)
Because no one is talking to him at school or at home, Henry is starting to feel pretty desperate for some human companionship. He can't wait to go visit Keiko at Camp Harmony—at least she'll talk to him.
The words were a strange comfort. Was this acceptance? Was that what this was? The sense of belonging was foreign to him, something alien and awkward, like writing with your left hand or putting your pants on inside out. (41.10)
Henry is so alienated and ignored in his own home that he's amazed when Keiko's parents treat him with kindness and warmth. He actually feels like he belongs with their family instead of his own cold parents.
For his father, leaving at age thirteen was a matter of pride, even though, deep down, Henry sensed a lot of emptiness and sadness along with it. Now on the bus heading home, he knew what his father had felt. Hurt and loneliness—but also a need to do what was right. (43.3)
Even though Henry doesn't see eye-to-eye on things with his father, he still understands that his father acts in certain ways because he's had a difficult life. He's dealt with a lot of loneliness and pain, and it's turned him bitter.
It'd been three weeks now, and no letter from Keiko. He knew that military mail had priority over all domestic shipments, especially letters going to someone with a Japanese surname—not to mention that mail in and out of the prison camps was notoriously slow. But this was troubling, on the verge of heartbreaking. (44.13)
Henry feels lonelier than ever when he stops receiving letters from Keiko. He's been counting on this lifeline to keep him from being completely isolated, and now it seems like she's forgotten him or moved on.