Chapter 277 of Mairimashita! Iruma-kun , titled , marks a major shift at Babyls Academy as Lord Sullivan's security devil, Opera, officially joins the school staff. The chapter balances emotional character development with the introduction of a new, high-stakes training arc for the Misfit Class. Plot Summary: A New Teacher Arrives

The existing Babyls staff are largely intimidated by Opera's fearsome reputation. While Kalego is visibly distressed at the idea of working with them, the cheerful Robin is thrilled to have a "junior" (kouhai) to mentor—a dynamic Opera surprisingly seems to enjoy.

Opera's new role serves multiple purposes—filling the gap left by the traitor Atori, keeping a close eye on the suspicious Shiida, and protecting the students while Sullivan is away at Babel Tower.

Students must reach the peak before their tea gets cold.