Megumi Amatsuka, known as Megu, is the middle child of the Amatsuka family and a member of the GJ Club alongside her older sister Mao. She has distinctive pink hair, usually styled in a bun secured with a blue ribbon, and matching pink eyes. Despite being younger than Mao, Megumi stands noticeably taller. She wears the standard school uniform shared by all club members.

Her personality radiates consistent calm, gentleness, and composure. This serene demeanor remains unshaken even during events that unsettle others, such as encountering spiders, highlighting her unusual lack of fear towards insects. Widely regarded as kind-hearted, nurturing, and angelic, her primary club activity involves preparing and pouring tea for fellow members, embodying her role as the group's caretaker. Megumi possesses considerable domestic skills: she bakes cakes and pastries, often prioritizing this activity over sleep, and is proficient in knitting, having created the club's costumes.

Specific sensitivities temper her tranquility. Discussions about her weight, documented as 50 kg, consistently provoke distress or anger, marking a significant personal insecurity. She also reveals a competitive streak, particularly during games, where her typically serene attitude shifts to intense seriousness. Deep affection defines her familial relationships with both Mao and her younger sister Seira. She worries occasionally about Mao's shyness and acts protectively, such as gently advising Mao on hair care to prevent tangles. Her interactions with Seira further demonstrate her supportive and caring nature as a sister.

Her background includes affiliation with a wealthy household employing maids like Mori and Komori, yet she personally engages in domestic tasks like tea service and baking. Her established traits—her serene presence, dedication to club hospitality, sensitivity about body image, and deep familial bonds—remain consistent throughout her portrayal.