Hartley

Hartley is caring, patient, and attentive to Batista's tendency to overwork himself. While she respects his dedication to Choujin research, she regularly encourages him to rest and enjoy ordinary life rather than measuring his worth entirely through his work.

She is supportive without being uncritical. Hartley recognizes how much Batista's scientific accomplishments mean to him, but she also sees the pressure he places on himself and tries to draw him away from it when necessary.

Her comparatively grounded outlook provides a contrast to the extraordinary world surrounding Yamato Mori. She values the possibility of building a normal future even while working alongside Choujin and researchers studying their powers.

Hartley is human, and no Choujin ability has been established for her.

Her expertise is scientific rather than supernatural. She works with Batista during his time as a Yamato Mori researcher and is familiar with his efforts to study Choujin biology and the possibility of artificially producing Choujin.

Hartley appears through the history of Batista's years at Yamato Mori, where the two work together while Batista pursues research into Choujin super-cells. Their professional relationship develops into a romantic one.

When Mado orders Batista's research discontinued because of a disastrous future she has foreseen, Hartley leaves Yamato Mori as well and builds a civilian life with him. The two marry, and Hartley later becomes pregnant.

Mado subsequently warns Batista that continuing the pregnancy will lead to catastrophe. Batista refuses to surrender another part of his future to her prophecy. Hartley dies following childbirth, while their child is stillborn; the loss becomes the central trauma behind Batista's collapse and his later obsession with overturning fate.

Batista Hoshi begins as Hartley's colleague and romantic partner at Yamato Mori. They later marry and attempt to build an ordinary family life after leaving the organization. Hartley's death becomes the defining loss that drives Batista toward increasingly extreme attempts to reject the future that was imposed on them.

Hoshi Sandek is Batista's older brother and therefore becomes Hartley's brother-in-law after her marriage.

Tsukiko Mado oversees Yamato Mori during Hartley's time there. Mado's prophecies profoundly affect Hartley and Batista's future, first ending Batista's research and later warning him against having a child with Hartley.