Whose Hello?

In a bustling city where everyone seems to know each other’s names but not their faces, you step into the shoes of a witty detective known only as the 'Faceless Avenger.' One day, a bizarre series of phone calls starts flooding in with people greeting you with 'Hello!' followed by strange requests and cryptic clues. Unravel the mystery behind these peculiar strangers while juggling humor, awkward situations, and a cast of quirky characters, all in search of their lost 'Hello.' Can you figure out who’s behind the curtain before the whole city is left speechless?