Nadeshiko Yaeno

"Nako-chan", as she is referred to in the anime, is Sumomo's closest friend. While innocently out for a walk, she discovers Sumomo's job as a Stellar Spinner. According to the rules of the collection game, as explained by Natsume, anyone who discovers the identity of a Stellar Spinner (other than her partner) must have their memory erased. Unable to accept this, Sumomo insists on finding another way. Eventually it is discovered that a one-time spell can be cast that binds the Stellar Spinner and one close friend together such that the friend's memory need not be erased. Though the decision was made quickly, Natsume reminds Sumomo and Masaharu that this can only be done once and since this one-time allowance has been made, they will have to be very careful from now on. Being the observant girl she is, Nadeshiko discovered Nona's role as a Steller Spinner when she put on her human glasses while in her Stellar Spinner form.

Source: Wikipedia