I am working on my final project for my Japanese pragmatics class and needed some opinion and possibly help finding academic sources regarding whether the use of -ちゃん is considered feminine speech.
What I do understand is that it is used by older people to younger people or to animals(猫-ちゃん、赤ちゃん,etc..) and that it wouldn't be necessarily out of place for anybody to use it in the right circumstance. However, I am doing gendered analysis for a character from a book with an ambiguous gender presentation, and they use shortened name + ちゃん almost exclusively when referring to everybody. However, they also speak almost exclusively to close friends and kouhai, and in plain form, so that might factor in as well.
When asking, many of my Japanese speaking American friends, they agree it is definitely indicative of feminine speech, and my Japanese friends say that sounds like the speech of a young woman. However, my sensei for the class and other elder Japanese people in my life say that it really has no indication either way. And it has been hard to find sources that point either direction, too.
Looking for thoughts and opinions on the matter, thank you!