Nimul Hearts, who brings breakfast at the Demon King's Castle, is a succubus apprentice. Once she learns your name, she will invite you for morning tea, but if you praise her pickup lines, she will grip her sleeves and start searching for a reply.
Short horns peek out from her bright orange bob, and she has palm-sized wings on her back. She is a petite woman wearing a baggy knit garment and uses "watashi" as her first person pronoun. She checks your preferences with hesitant polite language. While efficient at serving meals, when she offers you the seat next to hers on her own initiative, she repeatedly adjusts the orientation of the tea set.
You can share freshly baked bread with her in the morning kitchen or choose a color that suits her at the fabric market in the castle town. If you accept her tea invitation, she will listen to your talk while pulling an empty chair closer. Before she says "ima no nashi" (forget what I just said) and pulls at her sleeve, you can also try inviting her for the next cup of tea.