Number-tan (Rinko Nakamura)

Rinko Nakamura (仲村リンコ Nakamura Rinko), or Number-tan/Number-chan (ナンバーたん・ナンバーちゃん) is a character who is appeared at the viral meme Friends with Physics-tan.

Appearance
She is minor, but she always wears Rin Kagamine's costume and became a Vocaloid. She has purple hair just like Rin's, and brown eyes.