Thumbs down.
The FL overacted too much. I was distracted by the way she moves her mouth in an exaggerated manner, her over expressed immaturity, the overly cutesy way she tries to behave, her loud voice and generally, last but not least, the character's stupidity.

I don't know who's idea it was to have the female lead act this way, but she definitely does not match the very serious male lead character, and in fact, she ruins the viewing experience. This is one case of Japanese entertainment falling far short... again.