Character Concepts

Starting with the four main characters: Pōra, Era, Towaira and Kāri.
Pōra and Era are twins, they were very close as kids and grew closer after Era learns about Pōras depression and decides to help her with it.
Era and Pōra rarely have any conflict, since they both are tightly bound best friends and sisters. They also rarely fight due to Eras lack of interest in drama and Pōras hopelessness at resolving it.
However, for Towaira and Kāri, it's another story. They meet when Towaira makes a snobbish comment in the classroom and Kāri, offended by this, begins arguing with Towaira. They begin yelling and the teacher, fed up of their shit (as she should be), makes them get gym supplies from the gym for her, she assigns Era to supervise them. When they return, the two have stopped fighting, and everyone has gone to gym class and Era (who told her sister to wait for her) is expecting Pōra to join them down to gym.
The next bit is kinda a spoiler soooo basically they become friends!! And they have drama with one another occasionally but grow much closer over time, to become best friends!!
The four form a friend group and basically they are friends from now on!!