Suruga Monkey

S1, A6: Suruga Kanbaru, the school’s biggest star who has led the underwhelming girls’ basketball team to the national championships, begins to inexplicably stalk her upperclassman, Koyomi Araragi. When Hitagi Senjyogahara hears about this, she reveals that back in middle school, she was once so close to Suruga that they were known as the "Valhalla Combo."