-In the morning before school started- 

When Taeyeon opened her gate and got out of her house, she heard someone said: Hey, wanna walk to school together?

It was Leeteuk.

Taeyeon: Okay, sure!

As Taeyeon and Leeteuk walked to school, Taeyeon asked Leeteuk: So... How's your project going? I'm already done with mine.

Leeteuk: I'm almost done with it... And sorry, but I can't go recess with you today. Because I need to work on the project with Yoona during recess.

Taeyeon: Oh, that's ok. *then fake smiles*

When Taeyeon and Leeteuk entered the classroom, Taeyeon saw Yoona sitting on her chair with Yoona's things under her table.

Taeyeon angrily walked to her table and yelled: What are you and your stuff doing here?!

This moment, a few people turned around and looked at what was happening.

Yoona:*said calmly* Woah... Take a chill pill. I'm at your seat cause I asked the teacher if we could switch seats and she said ok.

Taeyeon:*said coldly* But I didn't say you can sit here. So get out of my seat.

Yoona:*said while standing up* Well, too bad. Besides, I already placed all your stuff on my desk. *points to her table where Taeyeon's stuff are*

This time, Taeyeon felt like exploding. So without thinking, she roughly shoved Yoona onto the ground.