I'm confused, is this futanari? It looks like it is, but maybe I need to watch the anime to be certain. It'd save me a lot of time if someone clarified this...

It's a trap

lol

Incestuous.

Added incest tag.

So, uh, if she's his sister, why's she surprised about the lack of breasts?

Grazere said:
So, uh, if she's his sister, why's she surprised about the lack of breasts?

its not his sister, its his cousin

Coremann43 said:
its not his sister, its his cousin

That'd be why.

[deleted]

Changed "You don't have tits?" to "No-Tits!" as the question mark is indicating surprise in the exclamation. Dekashiri and Naichichi are rude nicknames they use for each other.