"Like Two Peas in a Pod" centers on the lives of identical twins, Aoi and Akane, who share an uncanny resemblance but possess starkly contrasting personalities. Aoi is reserved, studious, and introspective, while Akane is outgoing, impulsive, and thrives on social interactions. Despite their differences, the twins are inseparable, navigating the complexities of adolescence together. The narrative explores their evolving relationship as they face challenges that test their bond, including academic pressures, romantic entanglements, and personal insecurities.

The story begins with the twins entering high school, where their contrasting traits become more pronounced. Aoi struggles with self-doubt and a desire to carve out an identity separate from her sister, while Akane grapples with the expectations placed on her as the more socially adept twin. Their dynamic is further complicated by the arrival of new classmates and friends who disrupt their equilibrium. Aoi develops feelings for a quiet, artistic classmate, while Akane becomes entangled in a love triangle, forcing both sisters to confront their vulnerabilities and fears.

As the plot progresses, the twins' relationship is tested by misunderstandings, jealousy, and external pressures. Aoi's introspective nature leads her to question whether she is living in Akane's shadow, while Akane's impulsive decisions create friction between them. The narrative delves into themes of individuality, self-discovery, and the enduring bond of siblinghood, highlighting how the twins' differences ultimately strengthen their connection.

Secondary characters, such as their classmates and family members, play significant roles in shaping the twins' experiences. Their parents, though supportive, often unintentionally exacerbate the twins' struggles by comparing them or favoring one over the other. Friends and romantic interests serve as catalysts for growth, pushing Aoi and Akane to confront their insecurities and redefine their identities.

The manga balances lighthearted moments with poignant reflections on adolescence, capturing the emotional turbulence of growing up. Through its exploration of identity, relationships, and the complexities of sibling dynamics, "Like Two Peas in a Pod" offers a nuanced portrayal of twinhood and the journey toward self-acceptance.