[Oengus why. Now Hijikata, the most prudish man in the Shinsengumi, has to explain what the red light district is to an apparently very innocent mind! But first things first. He taps the city map which is presumably a lot more detailed on his phone with his finger.]

This whole area is the city centre! The red light district is only this small part of it! And it's called that because of literal red lights, no blood or anything. Businesses there use them to attract customers' attention.

[Did he sidestep that nicely, or what?]