Well, having just reread both this series and Loose Relation, I'm having a damn hard time seeing how they're supposed to be connected at all unless there's something external to the works themselves saying so, like an interview with the mangaka. Loose Relation is entirely about magic in the modern day, and borrows primarily from Western esotericism with the occasional nod to other cultures' own occult traditions (plus references to Lovecraft's fiction that rapidly become more important). Meanwhile, Improper Capture Method features psychic powers in a vaguely-hinted-at alternate history/present, with no indication any of this stuff is outright magic (and it doesn't obey any of the same admittedly vague rules of magic from Loose Relation). I just can't see any internal connections between the two works.