Just a reminder that the reason No.6 is not a yaoi or shounen-ai is because it is officially not part of those genres (It’s genres are science fiction, dystopia officially). As in, the writer said it wasn’t. You can have gay characters without it being in a genre specifically stating that it is gay romance, which is what yaoi and shounen-ai genres state. No.6 is not a romance. Thus, it is not yaoi or shounen-ai.