It is rather difficult to gauge exactly the treatment of women in Japan during the Edo Period, aka the Tokugawa period, due to a marked bias against women in most historical studies up to this point. However, more recent studies have painted a picture that's more typical of much of the world at the time, in that women in higher society were bound by more rigid rules than the common people. The same holds true in China for the large part, to the point of almost all studies on Chinese civil law having usually assumed males as the parties of contracts. However, this is not to say women in Qing/Ming China had no rights.

As stated here: https://www.jsps.go.jp/english/e-ronpaku/2006/01_Fen.pdf

"When managing family matters in the public sphere, such as the purchase and sale of land or litigation struggles, women's role was basically determined by their status in the family system. Women could participate in these affairs only as 'widowed mothers.' However, when managing the family’s internal affairs, such as the division of patrimony or the establishment of an heir, although the father held the dominant status, we cannot overlook the power of mothers. In Huizhou documents related to the division of family property, one finds many instances of fathers and mothers jointly dividing the family property. This clearly illustrates the fact that the status and rights of women in legal matters varied according to context, that is whether they involved the families in internal or external affairs."

In Japan, meanwhile, the role of women, legally speaking, was fairly similar, with the family being of a higher order than any individual male or female. Divorce, for example, was initiated not through the male spouse, but through the coordinated activity of the families on both sides, and both families had equal standing in the marriage, with both spouses having the ability to remarry. An especially intruiging case involved a woman called Sui from Jōshū, who requested rienjō (documents related to divorce) three times on her own initiative.

Women in both countries did begin to receive some education later on, as marriage became more of a possibility to the lower classes. Parents would make an investment in order for their daughter to be trained in ethics, acquire literary skills, and understand the daily requirements of running a household, though this remained largely a luxury among the lower peasantry of both nations.

In summary, it cannot be said with much certainty in regards to legal protections (at least as far as my knowledge of the matter pertains) as to whether either country treated it's women better than the other, but both operated more within the framework of a male-dominated family than a strict male-female relationship, which did give women some legal rights. I apologize if this does not constitute a proper answer to the question.

sources: The place of publication is Tokyo, unless otherwise indicated.

• Asakura Yuko. "Buke josei no konin ni kansuru tkeiteki kenky shiron" (Statistical Research on Marriage among Samurai Women). In Edojidai no josei tachi (Early Modern Women), edited by Kinsei jyoseishi kenkykai (Society for the Study of Edo-period Women). Yoshikawa kbunkan, 1990.

• Rose, Barbara. Tsuda Umeko and Women’s Education in Japan. New Haven: Yale University Press, 1992.

• Takagi Tadashi. Mikudari han to enkiri tera (Notes of Divorce and Divorce Temples). Kdansha, 1987.

• _______. Mikudari han (Notes-of-Divorce Letters). Heibonsha, 1992.

• Yabuta Yutaka. "Moji to josei" (Literacy and Women in Early Modern Japan). In Iwanami kzanihon tsshi (Iwanami Lectures on Japanese History). Vol. 15. Iwanami shoten, 1995.