no - unless all the free seats in the back are sold out.

issue is - all the aisle/windows in the first several rows require payment - at least on lower fare classes (believe somewhere midway up the chain of fares or so, they are free for anyone). So if you book into one of those lower classes, seats in the first many Y rows - definitely the entire forward Y cabin, and the first few rows in the second, require payment. There are several rows in the back (probably starting in the low 30s somewhere on 789, at least) where you can select any seat. It’s possible on busy flights that these might be taken, though. Maybe ANA would help arrange for free seats for family if there is none in back - don’t know. Not my preferred area to sit, but we found 4 adjacent seats on both our flights. The paid seats also open to all for free at checkin - like Insaid upthread, I was able to snag seats in row 20 (first bulkhead row in Y on the 789) for me and my family at check in.