Why does the fifth personality bartender have a slogan that you can't drink for minors?

In Dowling's regulations on the use of spirits, the regulations cannot be used to entertain guests under the legal age. According to official website's inquiry, the bartender in the fifth personality is a female role, and there is a sentence in her lines that you can't give alcohol to minors. This sentence appears in the bartender's skill description, which means that her cocktail can give her teammates extra effects in battle, but minors are not allowed to drink it, which also implies the age limit of the game.