Keiichirō is a young man living alone after his family perished in a car accident while traveling to one of his live musical performances, a tragedy that caused him to abandon his career as a guitarist. This profound loss rendered him reclusive, though he retained a fundamentally kind disposition and regularly prayed for his deceased family. His solitary existence shifts when he discovers an inoperative android girl discarded near a trash heap during a rainstorm. Initially intending to dispose of her after learning she is an irreparable older model, he takes her home instead.

The next day, the android activates independently, preparing breakfast and exhibiting no memory of her past. Keiichirō names her Flower after the sunflower she held when found. Recognizing her short-term memory loss, he provides her with a diary to record her experiences, creating a narrative device for her perspective. Over subsequent weeks, their cohabitation deepens as he teaches her about daily life and the world, an interaction that gradually draws him out of his emotional isolation.

Through his relationship with Flower, Keiichirō tentatively reconnects with music, first attempting to play guitar again before fully resuming singing. Flower’s presence and eventual decline act as catalysts for his emotional healing, helping him process his grief and guilt over his family’s death. Her influence enables him to move forward, culminating in his return to musical expression despite the bittersweet outcome of their time together.

Keiichirō’s character arc illustrates a transition from withdrawal and loss toward renewed purpose and emotional openness, facilitated by his caregiving role for Flower. His actions, such as documenting their experiences through the diary and reintroducing music into his life, reflect his evolving ability to engage with the present.