Rem

Rem is a demon maid working in the Roswaal household alongside her twin sister Ram, and one of the characters most consistently tied to Subaru Natsuki's arc across Re:Zero. Introduced initially with a guarded, suspicious attitude toward Subaru, she becomes one of his closest and most devoted allies as the story progresses.

Role in the story

Rem's arc has been defined by an unusual structural wrinkle: for a long stretch of the series, other characters — and at points the narrative itself — don't retain memories of her the way they do other major cast members, making her presence a recurring test of who actually remembers and values her. That device gives her relationship with Subaru particular weight whenever the story reaffirms it, since her significance isn't something the plot ever fully takes for granted.

Why she keeps resurfacing as a touchstone

Even in stretches of the story that don't focus on her directly, Rem tends to function as a reference point for Subaru's emotional state — her presence, or the memory of her, is frequently what other characters or the narrative use to measure how much of "himself" Subaru has retained through difficult arcs. That makes her less a static supporting character and more a recurring anchor the series returns to when it wants to establish emotional stakes quickly.