When Kotonoha first started dating Makoto, they did not mesh well together. Makoto's thoughts were all over the place thinking about Kotonoha. He saw Kotonoha in the train in a bad mood and tried to hug her but she refused. Hikaru, who is in the same class as Makoto, happened to see this.
The name Katsura's sort of rare, as well. There's a lot of unusual names in your family.