Motoki Yaze

He is Kojou and Asagi's classmate. He is a member of the Far East District of the Lion-King Organization, and is the real observer of Kojou, the 4th progenitor, he is also Asagi's childhood friend and therefore often offers support to the latter for going after Kojou. He is actually an Esper whose special ability is called "Air Current Manipulation" which is the ability to manipulate air, vibrations and sound waves, but needs certain drugs or enhancers to strength his ability, he can also use his special ability to eavesdrop on anybody from any location most especially when listening on to Kojou and Asagi's conversation.

(Source: Wikipedia)