Jetpack Doesn’t Show Related Posts on ONE Post

I have Jetpack set to show related posts on my blog. However, on one post, for some reason, it does not show related posts. I have no idea why, but I would like to fix it. Here is the link:

Working correctly: http://yokai.com/kiukan/
Not displaying related posts: http://yokai.com/haimushi/

Please help me figure out what’s going wrong.