Morikawa, the 24-year-old who has won two Majors in the last 12 months, has a family background that takes in both China and Japan, via Hawaii and California.
Schauffele, three years his team-mate's senior, has a German/French father who once had Olympic dreams of his own, a German grandfather who officiated at the Olympics, and his mother was born in Taiwan then brought up in Japan.
The two golfers feel immense pride this week, both in representing the Stars and Stripes, but also doing so in a land that means so much to them.
"It's a true honour, I love Japan," said Schauffele ahead of this week's first round.
"My grandparents live in Tokyo so I made a lot of visits here and I've always enjoyed the culture and the food. I'm very excited to be here and to represent the USA."
The disappointment is that Covid protocols demand that his many local family members, who came out in force for the PGA Tour's Zozo Championship two years ago, must stay at home.
"It sucks," Schauffele said. "There's no nice way of putting it. Golf in Japan is a massive sport. It's a really, really a big deal.
"I always joke about it with Justin Thomas and Rory, because when we played at the Zozo we were paired together. It was like 10 deep on the first hole. When our names got announced it was like, holy smokes, are we at a Major Championship?!
"It would have been a massive show of people this week and selfishly, of course, I really want to see my grandparents. They're getting a little bit older in age and it would be really nice to see them."
It has also tickled Schauffele to observe his young compatriot at close quarters.
"He's very particular and there's an extreme attention to detail with the stuff that he does. It's very Japanese of him to be so fine-tuned, definitely one of his strengths.
"Everyone wonders why the streets are perfectly clean and everyone's in line here. It's like clockwork. We just kind of appreciate that. There's something to be said to the efficiency that's put in place here."
"Xander's hit it on the spot," Morikawa said. "Efficiency, respect. You embrace the culture and you feel respected. Aside from that, I also love how much they love food, that helps."
For all their high comfort level in Japan, Morikawa is clear about his aspirations this week.
"The end goal is to win gold," he said. "But getting to wear USA on your shirt, it's one of the biggest honors and it really means a lot because we play such an individual sport.
"We don't get to do this too often and when you do, you want to represent your country as best you can.
"Like Xander said, it's been really fun the past two days, but I'm really look forward to finally starting the tournament in a couple days."
Here's what else the pair had to say.
Memories of the last Olympics
Schauffele: "Collin was still in high school. It's been quite some time since the last Olympics. I haven't had the opportunity to ask what it was like to take the podium and stuff like that. Hopefully we can make those experiences for ourselves."
Morikawa: "I think if you asked Justin Rose, he puts that gold medal right on the top of his career, one of the best things he's done as a professional golfer. I sat on a plane with Fooch, who was Rosie's caddie at the Olympics, and he loves everything about it. I hope to make a lot of memories from it this week."
The pair on not staying in the Olympic village
Schauffele: "It's an hour and a half to two hours away. I wish I could experience the village, to see other athletes, how they train and things like that. That would be a really cool experience. But I'm staying 20 minutes away, otherwise you're waking up at three in the morning."
Morikawa: "It sucks not staying there. Hopefully we get more tries at this in the future. There's so many different rules that you have to follow this year that it just made sense to stay with the team, stay a little easier, have our transportation ready."
Schauffele on his father's Olympic dreams
"He was a decathlete hopeful. His accident occurred on his way to the training centre in Japan. He obviously didn't make the team, but we can joke about that now, so far removed from the accident. But if he could have been part of the opening ceremony, maybe he would have gotten emotional, because he put all his eggs in one basket for such a long time and it got taken away from him. I've tried to empathize with what he's done. If I got in an accident, wasn't able to play golf any more, same boat as him. Hopefully I can qualify for another Olympics so he can experience that and I think that would mean a lot to him."