Jisung and Changbin are sleeping on their table. Their seats are at the back of the class. Bangchan is beside the window, and there is empty seat in front of him. Beside him is Changbin and Jisung is sitting beside Changbin. After a few minute, the biology teacher enter the class. Chan is waking Changbin up and before he try to wake Jisung up, the girl who is sitting beside Jisung is kicking Jisung's table; she is Uhm Sa Nae, the class assistant. Chan just looking at her weirdly. But she is lucky that Jisung thought Changbin is the one who kick his table. Chan is looking in front. He is focusing the teacher words when he hear a voice,,,

~save me, someone...

Chan is startled, he looks around him and it looks like he is the only one who hear the voice. He try to ignore it but he hear it again,,,

~anyone...

"Maybe my imagination" he thought.

"Ok class, I am glad that all of you can come today."The teacher say while the student are looking toward their back. Of course they are looking at Chan, Changbin and Jisung. 

"What!" Jisung say while shooting a death glare at the people.

"Jisung..." Chan say quietly trying to avoid any trouble.

"Ok,,, ok... class.. attention please.."

"TURN YOU HEAD, YOUR BASTARD!!!" Changbin shout. Because of that, all the student quickly look in front. Chan just shake his head.

"Ummm.. thanks Changbin-ah... ok class..as I told you before we have an important work today. First of all, I want you guys to sit in pair. The pair will be the one that sit beside you.."

The order just make the students shout in pain as there are some student that hate their pair. Hearing the order, Chan quickly look at Jisung. His face change. He is looking at Changbin and Chan. Chan and Changbin will be in pair and because of that, Jisung will work in pair with Sa Nae. 

"So,, you guys will work in pair and I will give you guys a different topic. I want you guys to search for any information that related to the topic that I will give you guys later. And I will give your guys two days to finish the work." explain the teacher.

"Damn it!" Jisung say while kicking the air. Chan and Changbin just look at him. They are spending their time at the rooftop as it is PE time.

"I envy you guys, you guys can work in pair while I need to work with that girl." say Jisung.

Changbin just chukle. He know why Jisung feel restless. Actually, Jisung have a girl phobia. Only Chan and Changbin that know it. 4 years ago, Jisung had fall in love with a girl. Her name is Ji Soo. At first, Jisung was happy and he will tell the others about Ji Soo everyday. But one day, she break his heart. The three of them is strolling at the park when suddenly they saw Ji Soo kissing with a man. She looks very happy and was hugging the man when she realize Jisung was watching her. With that Changbin hurriedly bring Jisung far from that place leaving Chan there. Ji Soo was startled, She try to chase Jisung but Chan stop her.

" I does not want to see your face near Jisung. If I ever see you again, that day will be the last day you seen that man" warned Chan while pointing at the man that was hugging Ji Soo.

Starting from that day, Jisung start to became afraid of girls. It is really hurt when someone that you love stabbed you in the back. So he tried to distance himself from the other girls. 

"So,, what topic that you get Jisung-ah?" Changbin ask to break the silent.

"It's about mucous membranes. Even I also does not know what it means" say Jisung while pouting.

"So, your topic is also about the human defense system. We got phagocytosis." say Changbin while smiling.

"Talk about the topic, looks who came." say Chan while looking at the rooftop door.

They turns their head and they see a familiar figure. Uhm Sa Nae. 

"Umm,, you guys are here.... " say Sa Nae slowly.

"She looks scare." say Chan.

After thinking for a while, Changbin open his mouth.

"Can you come to my house tonight.You know my house right? We will be doing a group discussion. Can you? The three of us will be there."

"WHAT.?" Sa Nae shout.

"Don't you want to finish the work? I't okay for us but you as the the class assisstant, it must be hard for you to skip this work." Chan say.

"You're right.." Sa Nae say, aggree with Chan.