Whose Hellos Are These, Anyway?

In a bustling metropolis where almost everyone knows each other, the protagonist finds themselves in a bizarre predicament when they wake up to a series of strange letters addressed to them, each signed with an exuberant 'Hello!' from various quirky characters they don’t recognize. As they decipher each note, the player must navigate through a hilarious tapestry of misunderstandings, mistaken identities, and absurd scenarios. Each interaction reveals more about the colorful cast of oddballs residing in the city while unearthing a bigger conspiracy linked to a forgotten community event. Can you figure out whose greetings are behind these enigmatic letters before they land you in comedic trouble?