A young girl runs along a path in a village, which looks like an island. She is holding a watermelon and running quickly, looking happy. She seems about 7 years old. She opens the door of her house, drops the watermelon, which smashes, and sees another girl her age lying still, seemingly unconscious. She tries to wake her, but she doesn't move. She sees the rope used to tie from the bed where the unconscious girl is lying! The rope seems to lead into the room! Outside is messy. She sees her marble box fallen and the marbles scattered everywhere. She is terrified. Suddenly, she sees a baby, about a year old, lying stiff with a red and purple face. The baby's lips are perple black, likely struggling to breathe the baby is dead from swallowing marbles! The girl cries loudly, shouting for the neighbors to help and calling her parents!
"Huh!huh! The sound of rapid, fearful breathing startles her awake. She sits up quickly, clutching her chest, and realizes it was a dream. She looks at her pillow, wet with tears! She wipes them away and chuckles, "A dream again!" She gets up to shower. Walking past a photo, she picks it up and gently touches the image of the baby, about a year and a half old. She whispers, "It's okay! I've been in this new place for a long time now!"
She doesn't go to school to help out, as it is the day she needs to go to a certain place.
At a pagoda, there are many graves with just names written on them. We see likan, dressed modestly, approaching a grave with a baby's picture! She calls him "Little Brother!" She brings candy and talks playfully with her brother. Suddenly, Hana arrives. Hana pats kan's shoulder and speaks only of happy things to the deceased brother! Hana blames herself, saying, "Why didn't I die that day too? Living on is truly full of regret!" kan angrily refuses, saying if Hana talks like that again, they can't be friends! Hana changes from sad talk to good talk, telling the deceased brother not to worry, I will take care kan of everything! They agree that he has probably been reborn into some family by now! After talking about her brother until noon, they leave. Kan doesn't want to go to school. Hana invites kan to her house, and calls Siv siv to join them. Along the way, kan complains that she doesn't know how to find the real perpetrator! Hana just sighs. They arrive at the place where Siv siv is waiting. The three of them buy ingredients to cook at Hana's house. It is Siv siv's first time visiting Hana's house, and her reaction is as surprised as kan's. They make Khmer num Plae Ai (rice flour balls) and pancakes, which kan missed. Their activities are a joyful moment of friendship: watching movies, talking about the future. Hana's phone rings. It's Kim, that is her boyfriend. She checks the time And exclaims that she missed their date! Without delay, she tells them she has to go. "If you want to stay, stay! We'll meet when I get back."
Arriving at a shop, she sees Kim waiting! Kim missed her dearly and holds her hand tightly, as if they haven't seen each other in ages! They go on a date, visiting many places that day and Hana teach him some work of math,Hana asks, "Is Pud your friend?"
Kim hesitates but answers, "A friend!"
Kim can you call to Pud,? and I will call my friend. Kim tries to call but the call doesn't connect. He tells her, "I haven't been able to reach him since yesterday!" Hana sighs and says, "Then I won't call Siv siv either!" That evening, they date like a couple. Kim looks very happy. Then the pathway.
On her way back, she sees Tan. They look at each other strangely but don't say anything. he rides past, heading in the direction he needs to go. Hana chats with the Class President, mutu, and asks, "Do you really know tan's house?" The Class President is very confused, asking why she's suddenly asking. He tells her the address, assuring her not to worry, and says he won't invite her to tan's house again. He then chides her for not coming to school with her friends to help! He then chats in the class group, informing everyone that tomorrow they will clean the class, and the day after, they will arrange the booth. Seeing the message, kan remains calm, wondering how she can investigate since the camera is broken. After muttering to herself, it's time for work.
After work, Sister khai asks kan why she seems unhappy. She replies that she hasn't finished what she needs to do and tells her about the investigation. Hearing about kan's problem, khai asks, "Did you check the classroom again?" The hint suggests that someone was in the classroom while kan was sleeping! With the clue, kan thinks she will go tomorrow, since it's the cleaning day.
Soon, the next day arrives. Some classes have finished setting up, others are still setting up, and some are cleaning, like likan's class. She cleans near the window, looking for anything strange, but doesn't pay attention to the curtains! Just then, neaya(second vice-president of class12B) calls Tata and others to help her take down the curtains to wash. They start with other windows and come to the one kan is cleaning and looking at. Neaya asks, "What are you looking for, kan?" Hana watches kan from afar, thinking she's still preoccupied with the investigation! Li Da(first vice-president of the class) tells the boys to move the large cabinet to clean behind it! Kan is about to go look there ,when neaya exclaims, "This curtain is stained with something red and striped!" Tata comes to look and says, "It looks like blood!" , "It is blood!" kan quickly goes to look! The question she wants to ask is shouted out by neaya to their classmates, "Did anyone get hurt and wipe it on the curtain?" But no one did! Kan asks Tata and neaya to help wash that curtain. Hana looks at kan and the curtain, looking confused, but turns back to her own work.
Kan imagines that if someone hit the window from the inside, there must be an object used to hit it! But was the person crazy or intentional? There are no crazy students in the school! And if it was intentional, what was the motive? She closes her eyes briefly but doesn't sleep soundly. She is sure no one was there because everyone went out for breakfast! But what if they didn't go and came back into the class to do it? She shakes her head, refusing the idea, because when she woke up, no one was in the class. And when she went to the bathroom and came back, she heard the sound of breaking glass, looked over, and saw no one. At that time, she knelt down slightly, covering her ear, and looked left and right, wondering if anyone heard or saw, then walked to the window, seeing only the students playing ball, and didn't notice any running shadows near the class on the ground floor! She looks at the curtain again, realizing that what she didn't pay attention to was the curtain. She thinks further that the stain is on the left side near the wall, not on the right side where the curtain is pulled open and closed! Thinking too much gives her a headache. She shakes her head. Her actions make Tata and neaya look at her strangely, thinking kan is acting weird!
"Is someone intended to sneakily eat something, what would they do after eating?" She asks even though she knows the answer, and if it were her, she would do the same. But she asks to be sure, because the answer still leaves her hopeless, wondering where the discarded object is! They reply, "They would eat and throw the wrapper far away or hide it!" They ask her, "Are you not feeling well today?" But kan just smiles. Before washing the curtain, she takes a picture of the bloodstain! They help wash all the curtains and hang them to dry quickly.
After that, she returns to the class and sees them cleaning the area where the cabinet was moved from. She doesn't pay attention to the large hammer on the desk! They complain, "Why are there a few drops of scattered blood behind the cabinet?" Hearing that, she goes to look and sees the faint, partially wiped bloodstain. She takes a picture of the blood too. Just then, Mutu(president class) realizing her is continuing the investigation, pulls her aside and asks, "Is there anything strange in the investigation?" she gestures to him to be careful of his words. She says there were small bloodstains on the curtain and drops of blood behind the cabinet. She thinks someone was hiding and got hurt! Mutu says, "Just now, when we moved the cabinet, we found a hammer here." She then asks to see it. They speak softly and secretly take a picture of the hammer! Kan asks the Class President to help her keep the hammer safe in a desk drawer! And he doesn't refuse but wishes her luck in finding the truth quickly! But kan replies that she doesn't know what to investigate next! He suddenly smiles, pats her shoulder, and encourages her to try hard. He walks away and we can sees Hana staring at them , as if she wants something from kan.
"Kan! Are you really continuing the investigation?" "Yes! The exam is over, so I can investigate now!" Seeing kan's answer, Hana has nothing more to say.