limiter_(tsukumo_sana)

An accessory for Hololive English virtual youtuber Tsukumo Sana, who almost always wears it on her head like an ahoge. It's a thin, light-purple piece of material that sticks out from the top of the head and then spirals outward, similar to a mosquito coil. If a post clearly shows Sana not wearing her limiter, it's probably a case of the no headgear tag.