Astaroth Smoke is one of the few demon that works under the student council president of Babyls "Amelie Azazel." The student council president says they picked them for being interesting to Amelie. It is not known much about her past. Despite this they seem to put all of their faith, and time for Amelie as we know it with great admiration for Amelie.

(Source: Mairimashita! Iruma-kun wiki)