Miki wakes up in school to find Yuki standing over her, and then introduces her to “Megu-nee”, someone Miki can’t see, handing the invisible person a bottle of water that just falls to the ground. Miki wonders if her horrible experience at the mall was all a dream, but once Yuki shows her the music room—bright and clean to Yuki’s eyes but trashed and blood-stained to Miki—she realizes it was no dream.
Miki’s arrival means a disruption of the School Life Club’s routine, and also a potential disruption of Yuki’s presently stable condition. After being with Yuki for a while, she understandably has lots of questions for Rii-san and Kurumi, and she’s not entirely okay with “playing along” with Yuki’s illusions. That’s when Rii-san breaks out her threatening face, but it’s not played for comedy.
To Rii-san, Miki doesn’t fully understand the situation yet, or know Yuki well enough, to decide that it’s time for Yuki to “wake up.” Indeed, without access to profesional help or drugs, the way things are with Yuki are probably for the best (as long as she doesn’t descend too deep into fantasy). It’s not ideal, but it’s the best they can do.
More than that, though, to Rii-san and Kurumi, Yuki is more than just the crazy girl who sees things (like their dead teacher Megu-nee) that they have to keep an eye on and take care of. She also represents their beacon of hope, something crucial in their particular situiation.
Rii-san, Kurumi, and Miki can’t escape from the despair of their daily lives the way Yuki can without trying. And because Yuki is convinced the school is just fine and they’re in a club, she and she alone comes up with ways to break up the monotony of survival, like the mini sports fest this week, or the trip to the mall last week that led to the discovery of Miki and Taroumaru.
When she first arrived, Miki probably figured a good way to repay the girl who saved her was to help her “get better” from her illness, rather than accept and perpetuate her illusions. But now she realizes the three people who aren’t seeing things need Yuki there, seeing the people and places they can’t, reminding them of the world that was, and maybe one day will be again.
Understanding this, and that again, this situation is not ideal (ideally, Yuki would get professional help), but it’s better than simply living day-to-day not dying and fearing death. So she joins the School Life Club, and to her surprise, Rii-san welcomes her with an open hand, which may just be the first time Miki has embraced a girl’s hand since her friend Kei pulled away from her to go search for help.
Kei may be gone, but Miki is no longer alone. And she’s very glad about that.