Mizuka Irei is the owner of the Irei family convenience store and is a childhood friend of Misaki Senomiya. She is very knowledgable about Tanegashima, its residents, and rumors. At her store, Mizuka sells a special, passionfruit nikuman which is considered to be extremely repulsive and anyone who wishes to receive Mizuka's advice or dip into her vast knowledge must first purchase and eat one. This ritual is known as the "Lake Treaty." Mizuka is also paraplegic and wears a Power Suit leg supporter to help her walk.

Tone: Anything goes as long as you sound like you're around the mid twenties.