Her full name is Hikin Kuroki (黒木火金). She's a senior at Hashiraishi Highschool (柱石高校) and a 4-year-long member of the girls volleyball team. Owing to her working out and attending practice pretty much every day after school, she's quite fit and strong, with special attention to her thighs, glutes and back muscles. She has a long armspan of 226 centimeters (7 feet & 4 inches), useful for blocking incoming strikes or spikes.