In fact, the song is called Hawthorn Tree, and the beginning of the thirteenth episode is about 5 or 6 minutes. I don't know where to download the accordion version. I'll give you a link to download the background music (also the ending song) of this TV series (all copied):

qoolmj 5 btqn 7 BTP 0 bu 09 f 1m 1za

I downloaded other background music before, but now I don't have it, and I forget where I downloaded it. It seems to be in Baidu, hehe, I'll tell you when I find it.

Well, I found it,

/s/blog _ 50 D2 c8 f 50 1008v 90 . html

There are three background music, namely fate, love and the opening song (fate is the end of the film).

/Zhanbo/Yingshi Song/Daxiao-Mingyun.wma

/Zhanbo/Yingshi Song /daxiao-aiqing.wma

/Zhanbo/Yingshi Song/Daxiao-Title. wma