1st grader of Mihama Academy, the maid of Mihama Academy. Except when going to school, taking a bath or swimming, she always wears her maid uniform. She said that everyone told her to wear maid uniform as much as possible. Polite and has strong sense of responsibility, she never fails to accomplish any request from others. In her action dictionary, there are only 3 words “receive” – “confirm” – “execute”. Because of that, she often she takes a joke too seriously and causes a lot of trouble. Her favorite animal is the shark. The shark-shaped pouch which Michiru carries around is made by her. Sachi and Yuuji actually used to play in the park when they were little, making her Yuuji's childhood friend. She used to be an attention-needing, spirited and proactive toddler who loved to hear her parents call her good girl just because of attention. After her parents got better jobs and started working overtime, Sachi played with Yuuji every day in the park 'till he said they can't meet anymore. Soon after this, her parents apologized for not spending time with Sachi, and she became even more attention-needing. However, her happiness and endless needing for attention came to an end her parents died in a car accident, in front of her eyes and on her birthday. She still blames herself for the incident.