An Explanation for Diabetes

After Yui was sent to the Sakamaki brothers and things unfolded in less than a school year, her younger brother was also sent by the church. To get rid of him.

Two main problems, though, is that her brother was diabetic and he was also sent to the Mukamis.

With constant blood being drawn, and this strange boy in a school of vampires with the last name of Yui's, one of the Sakamakis needs to speak about it. Will everything work out fine between the siblings, or will things get a little bloody?
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Boy do I hate summaries like this, yet I'm doing them. I'll explain more about diabetes, so if your confused... read the book!