A young girl named Hiyori was overwhelmed by grief after her grandmother's death. Her persistent crying prompted her father to build a humanoid robot named Washimo, meticulously designed to resemble her grandmother, complete with dentures. Though initially moving slower than a rhinoceros beetle yet faster than a snail, Washimo unexpectedly possessed the capability to outrun a bullet train. This creation served as a direct intervention to provide Hiyori comfort and stability during her profound sorrow.