According to Japanese publication Tokyo Sports, the police stopped the cosplayer, asking, "Why are you wearing that mask?" The anime faced cosplayer replied, "That, I cannot say." The police, however, had the cosplayer write down his or her name and address.
The perplexing scene was supposedly happened upon by a Tokyo Sports writer, who noted just how odd—and freaky—the whole thing was.
渋谷に現れた謎の"アニメ顔"少女 [Tokyo Sports]