Consent
A child will ask if they want two waters because they need a grown-up's consent. Children aren't allowed to have whatever they want, they need to make sure it's okay and get consent first.
Picture the child finishing their first water. They look at a big stack of bottled waters, but they know better than to just take two more, they need consent first. "Excuse me, sir, could I please have two more waters?" the child asks.
しょう
うけたまわ
None
"Of course my child, you have my consent," comes the voice of the Shougun (しょう). The Shougun is very pleased by this child, because he expects everyone to ask for consent around him.
You need to make sure to get express consent from the Shougun before you do most things. Especially if it's something like taking more than you've been given.