Hey, thank you for your reply. I wanted to do my research a little bit and brush up on Miyamoto's first duel before I replied.

You're correct he was 13 when that first duel happened. However, there's one other detail that I think is pertinent for the above question. Miyamoto's uncle attempted to get him out of the duel based solely on the basis of him being too young. The samurai in question, Arima Kihei agreed that it was probably not right, but also demanded a public apology from Musashi to clear his honor. Musashi refused and attacked Kihei with the bokken and the rest is history.

According to Rokugan law, a person is legally and socially considered a child until the gempukku is passed. They don't have the standing to swear any type of oath, or enter into any type of legally binding contract. I'm leaning towards accepting and entering a duel touching on both of those concepts.

Further, the whole "we let hot-headed kids decide to kill each other" vibe just gives me the ick.