Only in Hoke-kyo that women can become a Buddha, for Hoon-kyo (the Sutra on the Buddha's Repayment of his Indebtedness) which we receive their kindness from mother's love (Reply to Sennichi ama Gozen)
但法華経計（ばか）りこそ女人成仏、悲母の恩を報ずる実の報恩経にては候へ（千日尼御前御返事）