The narrator describes Bokko-Chan saying ""the trouble was that she looked a little prissy but who can deny that a prissy air is an indispensable prerequisite for a beauty?"" What does he mean? Do you think being prissy is necessary for beauty? Do you think Hoshi is being facetious or not? Why?

By declaring that Bokko-Chan's prissiness is an indispensable prerequisite for a beauty, the writer was declaring that her charm, manners and composure, which complimented her beautiful looks, were traits absolutely necessary to attract customers to patronise his bar.

A prissy person is a charming, prim and proper person who is very well-mannered. This quality makes prissy people to be easily liked and attracted to which is one of the qualities of inner beauty.

Its my informed opinion that the writer Hoshi was wasn't being facetious - treating serious issues with flippant levity.

Instead the piece portrays him as a thoughtful, meticulous and shrewd businessman who knew what it took to grow his business and did it (by building a charming female robot bar tender) for his business to grow and succeed