According to the information on her wiki page, Saeko Busujima, with a height of 174 cm (5 feet, 8.504 inches) and a weights of 56 kg (123.5 pounds), she has a body amss index of 18.5, which is in the "normal range" which extends from a 18.5 to 25.
Also, her bust of 83 cm (2 feet, 8.677 inches) is 3.6 times larger than the inner radius of a NBA basketball rim.