Kei
Kei is Miki's closest friend and classmate. When the outbreak started, they were together at the mall and ducked into a storage room to hide. But Kei struggled with being cooped up—the waiting, the uncertainty, the boredom all got to her. Eventually she couldn't take it anymore and left on her own, leaving Miki her portable CD player as a parting gift before heading out into the chaos.
After Miki gets rescued by the School Living Club, she can't stop wondering what happened to Kei. It's one of those loose threads that haunts her, not knowing if her best friend made it out okay.
In the manga:In Otayori:
Content compiled by AnimeList.moe from publicly available sources.