Yuuki Machida

Yuuki Machida is an old acquaintance of Machiko that is mentioned in a flashback in Episode 1.

Plot
Machiko's friend in high school who changed how people address her because she believed her name to be too masculine. She was invited to Takashi and Machiko's wedding. Earlier, she married a doctor, but yearned to be with an old flame, causing her to cheat on her partner. Her surname is mistaken for Machiko's first name by Takashi, who is led to believe that Machiko is cheating on him, resulting in his outburst in Episode 2.