Shimeji Simulation is the second serialized manga by Tsukumizu (つくみず) of girls' last tour fame. It stars the apathetic Shijima and her contrastingly bubbly friend Majime as they go about their high-schooler lives.
If, like me, you're not a reader of slice of life or girls' love it could seem like there's nothing here for you, but you might be surprised as these genres are followed quite loosely; Shimeji Simulation is a surrealist work, initially in story and later on visually. Characters go about their day in a very mundane, almost detached manner despite all the anomalies happening around them, as if something like water floating one day, only to cease doing so the next is such a normal occurrence so as to be unremarkable. It's hard not to feel it very eclectic when it so often references art and philosophy, sometimes bringing them up directly, but always in that same uncaring manner.
Tkmiz draws very simple yet expressive characters. Both here and in girls' last tour you'll often get a zoomed out shot of someone, wherein you can get a better sense of the space they're occupying, I find this sets an atmosphere really nicely.
Given the premise and the way it presents itself, you wouldn't expect its plot to end up where it does, and by the end you're left with an almost faux sense of grandiosity. Some might reasonably dislike this major shift that happens halfway through, though I see it as a highlight, and even afterwards it remains as lighthearted as it was.