Haitatsusaki no Oneesan ga Kowasugiru

From Square Enix:
Being a delivery boy for "Delivery Eats" in a rural town isn't so bad, but one regular customer is a BIG challenge. She's a scary lady who looks intimidating and glares at the delivery boy every time he shows up at her door. Being an introvert, he can't help but run away as soon as the job is done. But one day, the scary lady finally speaks. Wait, is that the voice of his favorite VTuber?