Yuki Kurata is currently home alone while his parents enjoy their vacation. Assisting him with the household chores are his childhood friends, Mei Nekoyanagi and Sayo Inui. Mei is known for her outgoing and energetic personality while Sayo exudes a calm and knowledgeable demeanor. Being lifelong friends, they treat each other like siblings. Unbeknownst to them, a year from now they will be caught in a love triangle.