Merry Christmas Everyone!
These chapters come from the volume 1 tankouban. They were serialised in the magazine instead of online. The numbering is different from the online version which is what I’ve been using. Someone has nicely compiled a chapter list here: http://myanimelist.net/forum/?topicid=730727
Volume 1 Chapter 8 (chapter 7.5) – Download | Read Online
Volume 1 Chapter 13 (chapter 11.5) – Download | Read Online
Volume 1 Chapter 14 (chapter 11.6) – Download | Read Online