My Sister is My Girlfriend!? Sexual Relationship for Two Nights and Three Days 10

Editorial Review

★3.5 / 5 — henhenta editorial rating (our own assessment, not the DLsite official user score)

Sibling-romance comedy with a fake-relationship hook, Volume 10 of this series sits in a well-worn corner of the doujinshi landscape, where the appeal comes less from novelty than from how efficiently a premise sets up tension. The pretend-couple device is one of the most dependable engines in the genre, and here it is applied to a sibling dynamic for an extra layer of taboo.

What distinguishes this installment is its setup: a group trip where the narrator is ordered by his sister Nonoka to play her boyfriend. Nearly every scene has a built-in excuse for physical closeness, from staged flirting in front of others to the shared-bed sleeping arrangement. The synopsis suggests the story is driven by the narrator’s fraying self-control, with his protest of “We’re just acting!” setting up the central conflict between the performance and the real attraction underneath. Nonoka is framed as the dominant one, “always strong,” and the teasing, assertive-sister dynamic seems to be the main source of heat and humor. The framing of this as a first-time encounter between the pair also suggests a payoff built on escalation rather than a cold open.

As a 単話 (single-story) release with an English edition, it is accessible as a self-contained read, though the “10” in the title signals an ongoing series that presumably rewards familiarity with the characters. The synopsis offers little beyond the trip premise, so readers should expect a streamlined, situation-driven story rather than deep characterization.

Readers who enjoy teasing, sister-dominant dynamics, and slow-burn “we shouldn’t” tension inside a fake-dating framework will get the most from it.

Verdict: a competent, premise-forward entry that delivers exactly what its pretend-boyfriend setup promises, best suited to fans of the series and the genre’s familiar pleasures.