"Cheerful Amnesia" is a manga series that blends comedy, romance, and slice-of-life elements, centered around the relationship between two women, Arisa and Mari. Arisa wakes up in a hospital with no memory of the past three years, discovering that she has been in a romantic relationship with Mari during that time. Despite her amnesia, Arisa is determined to rebuild her life and reconnect with Mari, who remains supportive and patient throughout the process.

The narrative explores the dynamics of their relationship as Arisa navigates her new reality. Mari, who is deeply in love with Arisa, helps her rediscover their shared past while also adjusting to the changes in Arisa’s personality and behavior. The story balances lighthearted humor with tender moments, highlighting the challenges and joys of rebuilding a relationship from the ground up. Arisa’s cheerful and somewhat clueless demeanor contrasts with Mari’s more reserved and thoughtful nature, creating a dynamic that drives much of the series’ charm.

As the story progresses, Arisa gradually regains fragments of her memory, though the process is slow and often unpredictable. The manga delves into themes of love, trust, and resilience, emphasizing how relationships can evolve and endure even in the face of significant obstacles. Supporting characters, including friends and acquaintances, add depth to the narrative, providing additional perspectives on Arisa and Mari’s relationship.

The series maintains a light and optimistic tone, with a focus on the everyday moments that define Arisa and Mari’s lives. Their interactions are filled with warmth and humor, making the story both engaging and relatable. Through its exploration of memory, identity, and love, "Cheerful Amnesia" offers a heartfelt portrayal of a couple’s journey to rediscover their bond and move forward together.