What a waste of title man. With the same title but different promise, the story could revolve around like say, a random boy occult nerd decided to do summon as a joke but instead succeeded in which he summon his childhood friend that has gone for years and turned into monster girl in the process. The story, as well as the blood pact thing, then continues on exploring the childhood past as a monster girl or stuff, heck with some modification to the story he could summon his childhood friend one by one even