First of all, I have to tell that I'm not a fan of yuri or shoujo ai. This is the first manga of this genre that I have ever read, and I don't regret doing it.
The main disadvantage of this manga, unfortunately, was the art. Although, it seems normal since it was published in 1972.
To be short: What I liked the most at this manga were the feelings (Sadness, anger, love, fear). The most interesting character is Maya, whose personality I liked and whose way of thinking I admired.
The psychological part of the manga is well done. The characters are thinking about life itself, about their purpose, about happiness, about death.
I usually don't agree with revenge but I understand the strong feeling of hatred which makes revenge the purpose of living.
The manga also has a dark atmosphere to it, which I enjoyed. The drama may be a bit exaggerated but I like these stories where the emotions are too strong.
Overall this manga isn't a must read but it was enjoyable to me and it is a good example of a psychological about revenge, sadness and love.