Masao is a twentieth generation blade maker. His family left Kyoto centuries beforehand, but maintained the “music, idioms and accent” of the city. His marriage to Sumako is arranged, a marriage of convenience to their families. When Masao and Sumako attempt conceive, Sumako suffers two miscarriages. On their third attempt, Sumako successfully carries the child to full term and on April 23, 2003, she gives birth to their daughter, Mako.
As Mako grew, she often joined Masao in his workshop, watching as he forged and folded metal into weapons. At some point in time, he gifted her with a Hanbō staff.
On the day Onibaba made landfall in Tokyo, Sumako and Mako accompany Masao to the city to receive treatment for the cancer he developed. After his appointment, Masao and Sumako take Mako shopping. They buy her a pair of red shoes. Their visit to the park coincided with Onibaba's attack.
Masao struggles to keep up with Sumako and Mako and loses his daughter in the crowd during the civilian's rush to escape the creature. Masao and Sumako are killed during the chaos, leaving Mako on her own.