Ordinary Group Owner: "That's right. Touma Kazusa joined too, just a little before you did."
After seeing Setsuna Ogiso's message, Su Yunqing replied to her.
From the question in Setsuna Ogiso's words, it was clear that she and Touma Kazusa knew each other.
Judging by the timeline, they should have already been classmates at Hoho High School.
As the popular "idol" of the school, Setsuna Ogiso was widely adored, while Touma Kazusa was a solitary "piano prodigy" who rarely interacted with others. Since they were in the same year, it was perfectly normal for them to know of each other's existence.
However, that "acquaintance" was merely superficial.
To Setsuna Ogiso, Touma Kazusa was probably just "a somewhat mysterious classmate whose name and face she knew, and who was very good at the piano."
Given her personality, she might have noticed Touma Kazusa's loneliness and even felt a faint desire to approach her, but she had never acted on it. As for Touma Kazusa, Setsuna Ogiso was merely "a classmate who seemed rather popular."
With Touma Kazusa's withdrawn personality and indifference toward her surroundings, she most likely had not paid much attention to Setsuna Ogiso. They might not even have exchanged more than a few words.
Before Haruki Kitahara, Touma Kazusa's world revolved around only a handful of things: the piano, her mother, and little else. Afterward, it was not much different—there were simply two more people in it.
However, the Touma Kazusa in the Chat Group was not necessarily the Touma Kazusa from Setsuna Ogiso's world. Their timelines might not be the same.
The specifics would depend on what Touma Kazusa asked shortly.
Ordinary Group Owner: "@Touma Kazusa, want to come out and say hello?"
Based on Su Yunqing's understanding of Touma Kazusa, if this was Touma Kazusa from before