Eri Aikawa works as an editor at Marukawa Publishing, managing author Akihiko Usami's output, which includes mainstream fiction and boys' love novels. Her core task involves ensuring manuscript deadlines are met, frequently challenged by Usami's chronic delays.

Professionally composed and efficient, Aikawa exhibits intense reactions when deadlines loom, displaying visible distress and, on one recorded occasion, physically confronting Usami to obtain manuscripts. This dynamic arises from their long professional history; she was assigned as his editor early in his career at a Marukawa magazine. A pivotal incident solidified their trust: after Usami collapsed from overwork, Aikawa forcibly entered his home to check on him and retrieve his manuscript. When this scenario repeated twice more, Usami gave her a key to his penthouse for manuscript collection, marking deep professional reliance.

Beyond editing, Aikawa maintains friendships with both Usami and Misaki Takahashi. She occasionally shows fandom-like enthusiasm for Usami's work, with Usami confirming some novel scenes originated from her personal requests. She supports Misaki, expresses openness to his role in Usami's life, and voices relief that Usami has someone outside work.

Aikawa shares approximately the same age as Usami. Her appearance features auburn hair typically swept with bangs to the right and grey eyes. Her name incorporates meanings related to art ("drawing, picture") and logic ("reason, logic").