Kaoru was suffering from xeroderma pigmentosum (XP), an illness, which also might be described as the allergy to the sun, and was not allowed to be exposed to sunlight.

• 雨音薰，一个患有罕见遗传疾病的天真女孩，因为皮肤无法接触阳光，只能过着昼伏夜出的街头演唱生活。