As menstruation blood was highly taboo, special huts were erected for women in order to seclude them for a definite period, whereas the girl's puberty was celebrated by her family with a large attendance after her first menstruation. In the age of adolescence both boys and girls formerly spent the night apart, at houses other than their own, and boys visited their favorite girls at night. The form of marriage was the so-called ashiire-kon (a from of "bilocal" marriage) similar to that on Toshima Island as reported previously in No.3, Vol.14, of this Journal : after the marriage contract and even when there were already several children, both husband and wife spent the night at the wife's natal house or at the mawari-yado (nuptial house). The position of women was fairly high as compared with other parts of Japan, and a document 360-380 years old tells of the existence of a matrilineal family system on this island. The mother-son incest legend, which is found frequently in the origin myths of matrilineal societies, still remains in the folk-lore of these people. There also seems to have been a custom of sexual entertainment for strangers. 1. Puberty Rite 2. Menstruation Taboo 3. Mawari-yado (Nuptial House) and Love Affairs 4. Ashiire and Marriage Ceremony 5. The Status of Woman 6. Sexual Entertainment for Strangers 7. The Legend of Tanaba 8. Terms differentiating Birth-order of Sisters