She's Mamoru's online persona and Instagram famous.
Her name takes after NaN (not a number) and NaN3 (toxic gas) (at least until i find a better name tbh). She acts like a princess and her followers are her subjects, she's very cynical and often has a teacup in her hands.
She does a lot of things and talks about a lot of things too, from just her 'daily life' to criticising things and generally just posting content. She has a big fanbase, most of it is kind of gross but it's what Mamoru expected.
She really never appears in full body, and her dress is actually made from a curtain that Mamoru sewed himself. Her videos have very little lighting and are purposefully recorded in a lower quality than they should, though some photos and videos of certain things are higher quality.
Mamoru has kept this as a secret.