Player Narration and Game Master Narration

After Usagi's trials and tribulations on the road for the past several books, he decides its time to go home.  As he's walking home, he recalls the last time he saw his mentor, Katsuchi and how his mentor was attacked by Dogora students intent on avenging the default of their school by Katsuchi's pupil who just happens to be Usagi.

Usagi arrives just in time to see Katsuchi lose an eye and fall to his 'death' off a cliff.

To me, this could be the player narrating how things happened to his mentor. But it could also be a little back and forth between the GM. For example, the GM could ask, "So what happened to your mentor." at which point the player relays the information ending with, "And he was killed by the school" but the GM asks, "What if you saw him lose and eye and fall to his death above a raging river?"

I say this because Usagi decides to stop by his mentor's old dwelling and surprise, not only is the mentor still alive, but he's taken on students. When he fell, the river dragged him further downstream and he was saved by two orphans. One of those orphans had already left Katsuchi's training but was killed... in a duel against the very same Samurai that Usagi just dueled to the death before coming home. There's that foreshadowing again. We now know how there can be another swordsman with Usagi's style because it's his mentor's style and the man is still teaching.

By leaving areas of the character's background open, the player and GM allow each other some room to play off the character and their background elements. It's equally important though not to trash each others ideas but try to come to some accord. If the player insisted that his mentor was dead, or Stan decided yeah, that guy is gone, the readers would havel ost out on some great bits like the further volume Duel at Kitanoji. By allowing the background elements to influence current events, the whole has more fabric to it, it's a stronger material.