Sachiko Hasegawa was a tragic figure in the anime and manga series Pupa. She is the mother of Utsutsu and Yume Hasegawa as well as the former wife of Shiro Onijima.


She became pregnant with Yume a year after she had given birth to her son, Utsutsu. Knowing that she would be giving birth to a monster, she was worried for her son's safety,  and contemplated on aborting the baby before it could even have a chance to live. Things didn't exactly go to plan, however, and she ended up giving birth to Yume.

Sachiko hated Yume even when she was still only an infant. She always swore that Yume was watching her every move, and this drove her to the brink of insanity. She even took a pocket knife, and she tried to kill her with it. This didn't kill Yume, however; it only drove Sachiko further into madness. Sachiko also tried to keep Utsutsu as far away from his sister as possible, thus leading to negative feelings between her and her son.


  • Shiro Onijima (ex-husband)
  • Utsutsu Hasegawa (son)
  • Yume Hasegawa (daughter)


  • She apparently liked getting beaten by her husband, because she claimed that it made her realize "what was reality".