Q: What does Najma really say when she calls Jamil “dude?”

For some quick background: there are several ways to say the word “this” in Japanese, depending on how casually you are speaking.

When you are introducing a person (ex: “This is my brother”), one way you can do so is by using the form of “this” read as kochira (こちら）

In the example above Jade is not introducing anyone, but he is using the polite “this,” because he speaks formally all of the time.

Here we have Rollo using similarly polite forms of “that”: one for when someone/something is closer to the listener than the speaker (そちら, sochira) and another for when someone is far away from both people in a conversation (あちら, achira).

In this way we know that Idia is closer to Azul than he is to Rollo and that Riddle is far away from all three of them, simply from the form of the “that” that Rollo is using.

And these can be very important distinctions: For example, when fan translations alleged that Silver was going into the prefect’s bedroom, all because of confusion about the difference between “this” and “that” (more here ->)

The “this” that Najma uses when introducing herself as Jamil’s sister is not the polite こちら but the casual これ(written in katakana above as コレ for emphasis), which is very impolite to use with humans.

You can use it with objects (re: above, Jamil uses the same これ about a lamp that he is holding), but not people. Najma is essentially saying, “I am the little sister of this.”

(Here is an English-language article about this on Tofugu)

Jamil reacts with something close to, “What’s with looking at your older brother and saying “this”!, but as the English language does not have different words to denote different levels of politeness, their interaction had to be rewritten for EN.

That is where Najma saying “dude” came from, both a cute and effective solution.