I feel Kana Kurashina is not convincing

I watched March Comes In Like a Lion (2017) and Kana Kurashina was one of the parts I kept noticing. I do not hate it, but it did not pull me into the story. The role needs more detail, but the performance stays on the surface. Many moments pass very fast, and I do not remember much after them. For me, it does not feel very real in many scenes. Some emotions are too simple, and I cannot believe the character enough. This is only my personal view, but the performance changed how I enjoyed the film.