/vt/ - Virtual Youtubers

I've been thinking of writing a Moona incest fic since there's such an easy set up but there are two problems.
1. How would Moona's brother not recognize his sister? When he unknowingly simped for her in real life, her identify would have been obfuscated behind her live2D model. But in the fic she would obviously look exactly like her vtuber model.
2. How do I refer to Moona's brother in the story? Typing "Moona's brother" over and over would be grating, but making up a name like "Johnny" or something doesn't feel right either.