As far as Hisaki remembered, Takuya was happily married to her college sweetheart. She was a student in the language faculty.
They were together for almost a decade before Takuya proposed to her. Both of them had two sons that grew up to be so dear.
Around this time in Hisaki's previous life, she was already shackled to Igarashi Keigo. Even though her movement in and out of their matrimony home was not restricted, it didn't mean that she wasn't monitored.
The simple fact discouraged Hisaki to continue socializing with the people she was close to.
Hisaki didn't know much about the details of Takuya's relationship with the young maiden. The first time she met her brother's future wife was during the family dinner. Both sides introduced each other to their parents and discussed the young couple's marriage.