Miki is a second year student of Megurigaoka High School. She is seen hanging out with her best friend Kei, and the two seek refuge within a mall for a period of time when the outbreak happens. Eventually, Kei can't stand waiting around anymore and leaves. Miki spends some time alone until she hears the School Life Club girls on their trip to gather supplies, and decides to leave her shelter as well.

At first, Miki hates the way Kurumi and Yuuri just accept Yuki's illusions, but later comes to understand their reasons and warms up to Yuki. In contrast with her time in the mall, Miki becomes very proactive once she joins the School Life Club, and often goes on missions alone and battles the infected like Kurumi.

In Otayori:
Miki stays with the girls in the Circle from Saint Isidore University and is shown to still have flashbacks of Kei, her best friend, whom she feels guilty for leaving on her own.