This is a high-level survey of same-sex relations in China, Japan, and India. The article primarily covers male relations, so the following is rather brief.
China: “We know almost nothing about female same-sex relations in historic China, but evidently nobody cared much.” OK, there’s a bit more than that. The article notes the play Pitying the Perfumed Companion (see Stevenson & Cuncun 2013) and reproduces a 17th century woodcut of two women having sexual relations in a bathhouse.
Japan: This section has no mention of women at all.
India: The article notes the silencing effect that British colonial attitudes had on records of same-sex desire in India, that reverberates today in the form of an assumption that homosexuality must be a foreign import. However there is extensive material presented both on homosexuality and gender variance. The author includes religious imagery of paired (same-sex) deities, while noting that these images don’t explicitly speak to sexual relations. There are references in the Ramayana to women embracing “in the manner of lovers.” Medical treatises considered it possible for two women to engender a child, but assumed it would be deformed. There are multiple sculptural representations of sexual activity between women in temples, and the Kama Sutra includes sexual positions for female couples. Oral sex is regularly represented. At the same time, legal literature expresses negative attitudes towards same-sex activity. 19th century Urdu “Rekhti” poetry depicts love between women [note: other sources indicate that it was primariuly written by men]. Southern Indian cultures, especially in Tamil-speaking regions have literary traditions celebrating matrilineal and matrifocal cultures with strong themes of female friendship, marriage resistance, and even all-female societies, though these do not include sexual relations explicitly.