Characters in The Devotion of Suspect X

Tetsuya Ishigami

A brilliant mathematics teacher and Yasuko's neighbor, who is quietly devoted to her and pits his mind against the investigation.

Yasuko Hanaoka

A divorced single mother working at a bento shop, whose quiet life is upended when her abusive ex-husband returns.

Shinji Togashi

Yasuko's abusive ex-husband, whose unwelcome return sets the story in motion.

Manabu Yukawa

A physicist nicknamed Galileo who consults for the police and is drawn into the case through his old college friend Ishigami.

Also in A Midsummer's Equation A Detective Galileo Mystery, Silent Parade A Detective Galileo Novel, Invisible Helix

Shunpei Kusanagi

The Tokyo police detective who doubts Yasuko's alibi and brings in his friend Yukawa.

Misato Hanaoka

Yasuko's daughter, caught up in the events that follow her mother's ex-husband's reappearance.