Communication is very important in any relationships, no matter where you are and where you are from. Needless to say, in a romantic relationship. However, even though you understand that, you may want your loved one to understand your feelings before you communicate. In Japan, we have a proverb, 以心伝心 (I-Shin-Den-Shin), which means ones understand each other without words, equivalent to “That which comes from the heart will go to the heart”. This word was originally from Zen Buddhism. Some Japanese think this is also an important factor in a relationship besides communication. The closer your relationship with your partner, the more important it could be. Especially Japanese women think more strongly that way.
I personally think 以心伝心 is one of the ideal forms in a relationship. My husband is from America and always says “communication is important”. I understand what he says but sill I tend to think this way and remain silent for a while even when there is something that bothers me in our relationship and I know communicating would actually be the easiest and fastest way to solve them. But even so, I want my husband to understand or at least try to understand how I feel before I speak up.
Also, Japanese women may be known as quiet, reserved, modest and so on by the image of some Japanese books or movies. It is probably true and you may think so especially when you compare them with women from your country. But it doesn’t mean they don’t get angry or so, of course, Japanese women get angry and emotional. But it may be difficult to sense whether they are angry or not because they may not show their anger. However, Japanese women could be passive aggressive in a relationship. That is, your partner suddenly starts ignoring you, or even though she doesn’t complain anything to you, her attitude is obviously different or upset. She may even say nothing is wrong with her even if you asked. You may have no clue what she is mad at, or what you did to her, even though you noticed that she acts differently. She wants you to know what she is angry at and simply doesn’t want to be asked why or what. She may be thinking why you don’t understand?! This may be different from images of Japanese women you have but this is one of the characteristics of many Japanese women.
Hope this helps you understand some sides of Japanese, especially Japanese women.