a japanese song music video

by Suzume

it's a slow song, similar to a soft happy country song. it's sung by a girl.

The video consists of her standing on a drama stage as she holds a diary to her chest while singing out to the audience. along with her there are other girls in the video who are singing to their boyfriends who are sitting in the audience. At the end, all the girls are standing together singing, while the camera is situated behind the guys while focusing on the girls.

I heard the song on animax. Could someone please tell me which song this is? Because it is a very sweet song. >///<