Yoshinoya-sensei's bawling is originated from Matsuki Miyu's ”congratulations!" tweet: http://twitter.com/whitesincerely/status/423119236051906560
See also these nicopedia and pixpedia.

Added to pool #4467, because Matsuki Miyu's last blog entries mentioned that if she ever recovered, she wanted to get married. That's never going to happen now.