In Tonikaku Kawaii (Fly Me to the Moon), the female lead character Tsukasa is usually seen wearing an oval-shaped purple headdress:
What exactly is this accessory? I might have surmised that this is a type of hairnet, except that Tsukasa is seen wearing this headdress with her long hair let down. In fact, she takes off this headdress when she gets ready to sleep and ties her hair up into two side-buns:
Of course, I am not particularly knowledgeable about these kinds of accessories. Can someone enlighten me about what exactly Tsukasa is wearing?