Who Is That Masked Man?
Usagi's Joy: A Love Letter from Tuxedo Mask
Usagi kangeki! Takishido Kamen no rabu reta
"Usagi receives a love letter from Tuxedo Mask, stating that he'd like to meet her. But she soon finds out that all the girls in town received the same letter, including Naru, who believes that Tuxedo Mask is Masato Sanjoin." (source)