Character Relationship Map: Mirai

Characters

• Kun (played by Moka Kamishiraishi) — protagonist

  Jealous four-year-old boy who time-travels to understand his new sister.

• Mirai (played by Haru Kuroki) — protagonist

  Newborn sister whose arrival changes family dynamics and sparks Kun's growth.

• Father (played by Gen Hoshino) — supporting

  Architect father in Mirai who balances work and family life.

• Mother (played by Kumiko Aso) — supporting

  Executive mother in Mirai who struggles to connect with her children.

• Grandmother (played by Yoshiko Miyazaki) — supporting

  Kun's grandmother who guides him through magical time travel in Mirai.

• Young Man (played by Masaharu Fukuyama) — supporting

  Mysterious young man in the garden who represents time and memory in Mirai.

• Baby Mirai (played by Kaede Hondo) — supporting

  Infant sister whose arrival changes family dynamics in Mirai.

Canonical Relationships

Family, romantic, and professional connections based on plot evidence.

• Mother → Grandmother (Family Daughter) — Their difficult childhood interaction helps Kun understand Mother.

  In the past, the young version of Mother asks her mother for a pet cat and is scolded by her.

• Father → Mother (Family Spouse) — They share responsibility while facing conflicting work and family demands.

  Father and Mother jointly manage the household and their children after Mirai's birth.

• Mother → Mirai (Family Mother) — Mother's parental role changes the family's daily balance.

  Mother returns to the office after Mirai's birth, while the family adjusts to caring for the newborn.

• Father → Mirai (Family Father) — Father's attention toward Mirai contributes to Kun's jealousy.

  After Mirai is born, Father's attention is focused on the baby while he works from home.

• Mother → Kun (Family Mother) — Their strained bond gradually gains empathy through Kun's time travel.

  Kun is born to an executive mother, and Mother shows him photographs from her childhood to help him understand her.

• Father → Kun (Family Father) — Father struggles to balance remote work with parenting Kun.

  Kun is born to an architect father, and Father helps him practice riding a bicycle.

• Kun → Young Man (Temporal Future Self) — Young Man is revealed as Kun's future identity.

  Kun discovers that the eighteen-year-old man at Isogo Station is future Kun.

• Mirai → Baby Mirai (Temporal Future Self) — The two entries represent Mirai at different points in her life.

  Baby Mirai appears during Kun's station ordeal, while an older Mirai later arrives to take Kun home.

• Kun → Grandmother (Family Grandson) — Time travel lets Kun witness his grandmother's relationship with his mother.

  Kun travels to the past and meets his mother as a child, whose mother is identified as Kun's grandmother.

• Kun → Baby Mirai (Family Older Brother) — Kun's protective response marks his acceptance of his sister.

  Kun rescues Baby Mirai when she is about to board the train to Lonely Land and realizes that he is her older brother.

• Kun → Mirai (Family Older Brother) — Their sibling relationship drives Kun's emotional growth.

  Kun initially resents the attention given to newborn Mirai, but he finally acknowledges that he is her older brother after rescuing her at Tokyo Stati...

Story Analysis

A jealous child uses journeys through family memory and time to understand his sister, parents, and place within generations.

Plot Progression

1. A Sister Enters the House — Kun enjoys his familiar home until Mirai's birth redirects his parents' attention. His jealousy leads him into the garden, where impossible transformations begin.
2. Mirai From Tomorrow — Kun encounters an older Mirai in the garden and helps her put away the Hinamatsuri dolls. The experience begins to connect his frustration with Mirai's future.
3. Lessons From the Past — Kun visits his mother's childhood and witnesses her conflict with Grandmother. A later journey to a rural workshop helps him learn the confidence needed to ride a bicycle.
4. The Station of Isolation — A family-trip dispute sends Kun into a strange station and onward to Tokyo Station. His inability to name his parents leaves him facing the threat of Lonely Land.
5. A Family Seen Through Time — Kun saves Baby Mirai and is guided through the family's past and future inside the tree. He returns with greater empathy and joins the family trip.