The core of the manga is the relationship between Ageha and the "fluffy and innocent" Regulus. Ageha transitions from a spoiled brat to a doting, responsible older brother.

One day, after collapsing from a fit of rage, Phil hits her head. When she wakes up, she has a fever... and the complete memories of her past life: a 21st-century Japanese woman who worked as an elementary school teacher.

, the five-year-old eldest son of a count in a corrupt empire. The Problem:

The protagonist, [protagonist's name], is a complex character with a rich backstory. His memories of his past life influence his actions and decisions in the present, often leading to humorous and heartwarming moments. The younger brother, [younger brother's name], is portrayed as an adorable and innocent child who brings joy and light into [protagonist's name]'s life. The supporting characters, including [other family members and nobles], add depth and complexity to the story, highlighting the intricacies of noble society and the challenges faced by [protagonist's name].

Ageha Kikunoi, the neglected son of a corrupt count, regains memories of his past life as a Japanese man. He realizes he has been reborn into a world where his future is grim: his adorable half-brother, Regulus, is destined to kill him in a succession dispute. Rather than fleeing or becoming a villain, Ageha decides that Regulus is simply "too cute" to let go bad. He uses his past-life knowledge—specifically in cooking, sewing, and modern industry—to raise his brother right and save their struggling territory.