Whose Hellos Are These, Anyway?

In a quirky city where every greeting has an inexplicable power, you, a cynical investigator with a knack for unraveling bizarre mysteries, are called in to solve a growing phenomenon. People start receiving mysterious 'hellos' from unknown senders, causing unforeseen events in their lives - from spontaneous celebrations to absurd predicaments. Your task is to navigate through various neighborhoods, engaging with eccentric NPCs, solving riddles, and piecing together clues to uncover the source of these peculiar hellos. Each interaction can lead to humor, wisdom, or outright chaos as the lines between friends and foes blur. Can you decipher who's saying hello and why their greetings are causing such havoc in this oddball community?