Machi is Ayane's older sister. She may look innocent, but she is actually something of a sadist. She enjoys torturing people with her voodoo doll -especially her little sister- enjoying their pained expressions. Whenever she has to get things done, she tends to use the most dangerous way to do so.
She has a weakness though: her age. Machi is very sensitive about it so whenever someone calls her old, she gets a shock. Machi has an eye on Ikuto because of that, thinking she should be getting married soon.