Taking the same flight home with a friend?

[gundamsilvermoon]

For the past nine months I've been living here in Japan as an exchange student. I'm supposed to go home in August, so I plan on booking a flight back to the United States soon. However, my best friend in the United States wants to come visit me for a week after my semester is over, and I suggested the idea of the two of us taking the same flight home. Whether I buy a one-way ticket or a round-trip without using the return ticket, is it possible for us to book the same flight from Japan to the United States, and maybe even get seats together?