Magic is the common term used for Vymar-real waves (VRWs). VRWs are caused by resonance between quantum fields. VRWs can interfere with particles in unexpected ways.
Awakening
Neuron pathways often interfere with VRWs. For this reason, some living creatures are sensitive to the presence of VRWs. Such creatures are called "awakened". Some awakened creatures are capable of consciously interfering with VRWs. This can manifest as spellcasting, alchemy, divination, astral projection, or conjuration. All youkai are awakened.