Whose Hellos Are These, Anyway?

In a bustling, quirky city where every citizen has an exaggerated persona, you play as a retired detective turned overly sarcastic greeting card writer. A mysterious series of unsolicited greetings — strange notes saying 'hello' — begin appearing in unexpected places, causing chaos among the locals. It’s your job to unravel the identity of the 'Eager Greeter' behind this phenomenon while navigating through colorful characters, unorthodox leads, and comedic twists that challenge your detective skills. Can you solve who’s spreading these hellos before the city devolves into anarchy?