Junna Tono is the male protagonist of the story, a high school student attending Sakurahama Private School. He is characterized by his popularity among his peers, being well-liked by both his female classmates and some of his male friends. His life at school and at home is pleasant, allowing him to seemingly forget a severe past, but this past is central to his identity and the challenges he faces.

Background and Personality
Junna lives with his twin sister, Senna, after a tragic traffic accident took the lives of his parents and robbed him of his memories. Despite this loss, he has built a happy, ordinary life with his sister, relying on her support as she relies on his. He is depicted as a hard-working individual, motivated to support himself and Senna due to their situation living alone. Initially, he is content, but as the story progresses, he begins to experience flashes of the memories he lost, which disturbs the peace of his present life.

Motivations and Role in the Story
Junna's primary motivation shifts from maintaining his pleasant daily routine to uncovering the truth hidden within his lost memories. He finds himself caught between his past, present, and future, needing to understand what is real. The narrative centers on his difficult position as he learns that his current world may be a creation born from a wish. He discovers that he and Senna used a mysterious dial to wish for her existence, which came at the cost of his parents' lives and changed his relationship with Haruhi, who was originally his sister but became a childhood friend in the new world. His role is to decide which reality he wants to live in: a world where Senna exists as his twin, or one where his parents and Haruhi as his sister exist.

Key Relationships
Junna's most significant relationship is with his twin sister, Senna. They live together, support each other, and are extremely close, with Senna being very fond of her brother. Their bond is the emotional core of the story, as her very existence is tied to his memories and wishes. Another crucial relationship is with Haruhi Inohara, a girl who transfers to his school and claims to be his childhood friend, calling him "Onii-chan". She is deeply attached to him, and Junna's confusion about her stems from the truth that she is actually his biological sister in the original world he has forgotten. He also interacts with Tomo Kishida, a mysterious classmate with a stoic expression who reveals herself as the Keeper of Time, guiding Junna toward making his final decision.

Development
Junna undergoes significant development from a boy who has accepted his amnesiac state to one who actively seeks the truth. Initially resistant to remembering, he becomes troubled by inconsistencies, such as photo albums that contain pictures of Haruhi instead of Senna. His development culminates in a crisis where he must confront the consequences of his and Senna's shared wish. He experiences anger and frustration upon learning that his happy life was built on a wish that erased his parents, but he ultimately strives for a solution that does not involve sacrificing one family for another. In the end, he seeks a new wish that allows for a different future.

Notable Abilities
Junna does not possess any overt physical or supernatural abilities. His defining characteristic is his connection to the "dial," a mysterious artifact that can grant a person's strongest desire. His ability, alongside Senna, to make a wish that fundamentally altered reality is the central mechanism of the plot. He later demonstrates the strength of will to try and use the dial again not for personal gain, but to find a compromise that allows everyone he cares about to exist in some form. His true ability is his capacity to bear the weight of this choice and his determination to create a future where all his loved ones can be happy.