Angel's Recipe Book

The Angel's Recipe was a "recipe book" filled with procedures for developing experimental drugs not yet available to the general public. These drugs ranged from poisons to medicines and cures. The book was developed by the Tenkai Group, and was owned by Issei Tenkai (and formerly, his parents) for a significant amount of time until it was purchased by Tsukasa Oyashiki.

Contents
The Angel's Recipe reportedly contained information on possible cures for hypogeusia and ageusia, two disorders that result in a loss of the ability to taste.

It also contained a description of the Megatoxin X pesticide, where it is mentioned that mixing it with normallium would produce a toxic gas known as fatallium.