PERSONALITY
Chidori's facial expressions describe her pretty well. She is a very timid girl with hidden emotions and a closed off attitude. Chidori starts off being extremely quiet, only pointing out the obvious when speaking to others. Once Junpei runs into her, she starts off being extremely cold. She continuously comments on the fact that he is in her way. This causes her to get a little bit irritated, asking him to move, etc. As he pushes himself into her life more and more, she starts to open up a little bit. I feel like no one has ever given her the time of day, or at least never asked her about her own feelings and interests. I feel like this because Chidori seems very surprised when Junpei is interested in knowing more about her. She is a very confused character, even saying how she feels confused and unsure of who she is and how she should act. She is pulled between what she wants and reality, therefore causing her emotions to get mixed up and become lost.
Why is Chidori like this? Well, from what we have gathered throughout the series, she seems to have had a very rough childhood. She was constantly in and out of the hospital, which probably describes why she has a lack of social skills. I don't think she was able to really be around kids her age, nor was she able to really learn how to play. Chidori had to deal with her emotions all by herself, and therefore she became closed off. We never hear her speak about her parents, so it's hard to say if they were even in her life, or supportive at all of her in general.
Chidori also tells us that she knew from the moment she got her Persona, Medea, that she was going to die. I think the fact that she knew she was going to die young also could have changed her personality to become closed off. What would be the point in getting close to someone, just to eventually lose them? This would make a lot of sense, especially because she is afraid of her emotions for Junpei when they first start developing.