Synopsis: The Big Stepsis Who Wants To Be A Big Sister Vs. The Little Stepsis Who Wants To Be Yuri

When Shio gets back home, she finds out that her mom has tied the knot again and is leaving for a work-related trip with her new beau. As for Shio, she now has to look after her step-sibling Kafka, who is just a day younger than her. Fearing that Kafka may replace her place as the elder sister, Shio remains watchful. Nevertheless, Kafka is determined to make Shio, her first crush, fond of her.