The movie opens with Ju-young arguing with her husband over her son Hee-chan's behavior at
school. She cares about her son but is struggling to create a balance between her personal and
professional life. The school authorities call her to discuss the situation. When she sees her son's
diary, in which he has written about his feelings about being left alone and drawn her caricatures,
she gets overwhelmed and leaves after handing the teacher some money. She has been so engrossed in
her work and making money, that she thinks money is the solution to every problem.
Soo-Jung is a sign language news interpreter. She is practicing sign language with her
deaf sister Soo-Eun, who works as a costumed mascot. While walking around the theme park,
Soo-Eun sees Sang-Gyu, a clumsy artist dropping his art supplies as he walks.
She helps him pick up his things and instantly is swooned by his good looks. She hands him
the painting he had dropped in the rain the other day before bidding him a cheery goodbye. Soo-Jung
goes shopping with her boyfriend, Jin-Woo, for Soo-Eun's birthday party. There Jin-Woo tries
yet again to bring up the topic of marriage, but he cannot build up the courage to propose to her.
Soo-Jung is waiting for him to ask her the big question. Walking back home, Soo-Jung expresses
her concern about Jin-Woo's profession as a firefighter. She is worried about his safety as
it is too risky. However, Jin-Woo is adamant. They are celebrating Soo-Eun's birthday.
She didn't quite like the gift they got for her, so they promised to set her up for a blind date.
But Soo-Eun refuses, saying she already has a boyfriend. She shows them the picture of Sang-Gyu,
which she had clicked in the park. But in reality, she is afraid to tell him her feelings. She is
insecure about her burn scar and the fact that she has difficulty communicating. She expresses
herself to Sang-Gyu only through gestures after putting on that outlandish mascot costume. Once,
he offers to paint her in her mascot dress. He is curious to see who is under the costume,
so he urges her to take the mask off as it is sweltering. When she doesn't, he teases her by
asking if she is a man underneath that costume. She shows him her long hair and nice legs,
but he keeps being pushy till she shows him her bra strap. Embarrassed, he asks her to
stop. After he is done painting her, he hands it to her. She hugs him out of happiness.
Ju-Young is driving Hee-Chan to school. She forgets to stop at the school stop, and stops
when Hee-Chan reminds her. He is irritated with his mom and leaves the car without saying goodbye.
Ju-Young feels terrible, not only for being forgetful, but she feels as if
she is failing her son as a mother. This makes her step on the accelerator a little too hard,
and her car meets an accident. At the hospital, Hee-Chan refuses to see his mother.
The mother-son relationship has taken a toll over the years. The next day Hee-Chan visits his mother
at the hospital. It is after a long time that they have had a hearty conversation. She makes
Hee-Chan promise to always show his diary to her. Because it is there, he writes about his feelings
and the day's events. She wants to understand her son more and make up for all the lost time.
Hee-Chan is also warming up to her. In his innocence, he wishes his mother would remain
sick, so he could spend more time with her and see her whenever he wants.
At the supermarket, Suk-Hyun works at the purchase counter. She is unhappy with her
unemployed boyfriend, Ha-Seok. His card is maxed out, and he doesn't have any money
even to purchase the groceries. Suk-Hyun wants to break up with him. Infuriated,
Ha-Seok shouts at the customer standing behind him and leaves. Suk-Hyun apologizes to the customer on
his behalf. We also see him getting beaten up in the boxing ring occasionally in the movie,
even after he plays dirty and tries to punch his opponent off guard. He gets paid to act like
a human punchbag for the boxers. After one such fight, he is walking back home when a random woman
approaches him, asking for his help. She wants him to tell her boyfriend she is breaking up with him.
When he does that, the boyfriend starts crying. She asks Ha-Seok to hang up, but he feels bad for
the guy and continues the conversation ending it on a positive note. He starts to leave when the
woman stops him and gives him money for the task. This gives him an idea of opening a 'separation
agency' that helps couples break up. Jin-Woo asks Soo-Jung to meet him for
dinner. He plans to propose to her and has even purchased a ring for her. But he loses it as he
gets slammed by the fellow firefighters who were rushing out for an emergency.
Soo-Jung is waiting at the restaurant when the fire alarm goes off. Everyone is evacuated, but
Soo-Jung stays behind. She is still waiting for Jin-Woo thinking he is finally going to propose,
and all this is a setup by him. It turns out to be an actual fire, and Soo-Jung gets furious
with Jin-Woo. She even beats him up with her purse. She has already waited enough. Jin-Woo
takes her to the movies. She is still furious. By the time the movie ends, they are laughing,
and their relationship is restored to normal. The temperature is soaring, so Soo-Eun takes a
drink break. Sang-Gyu almost catches her without her mask because of her hearing impairment,
but she manages to put it on before he sees her real face. Sang-Gyu wants to see her face, so he
tries to force the mask off her face. Before he can do so, her fellow mascots, the seven dwarfs,
start throwing empty juice cans at him and beating him up with squishy hands and feet.
Hee-Chan is taking care of himself because his father doesn't. He runs out of cereal,
so he tries to take another box out of the cupboard. There behind the cereal box,
he stumbles upon his mother's diaries. He begins reading them and learns how his mother raised him
even when his father wanted her to abort him. Hee-Chan feels happy as he reads how his mother
wanted to raise him better than his parents, but then he lets out a sigh when he reads that
his mother wanted a girl. The bond between them is strengthening. However, fate has something
else planned. The doctor tells Soo-Jung that she has cancer. Her health deteriorates in the days,
so Hee-Chan takes it upon himself to care for his mother just as she did for him.
Ha-Seok starts getting clients. It can get complicated too. At one time, he gets slapped,
and the other time he tries communicating with a foreigner who doesn't understand him.
He sometimes lends his shoulder to cry on and at worse times, tries to stop the person from
committing to eternal sleep. He meets Suk-Hyun after work. But she is not interested. Even though
they broke up, he doesn't believe they have and promises her to meet on the weekend.
One day, Soo-Eun is returning home on a bus when Sang-Gyu boards the bus. He doesn't recognize
her. Regardless, she tries to hide her face. There is a massive fire accident at a warehouse.
Jin-Woo, with his team, is rescuing the people stuck inside. They find a man unconscious and
help him get out before the fire spreads, but there is an explosion. Soo-Jung is relaying
this news while worrying about the safety of Jin-Woo. She rushes to the hospital and gets
scared when she sees the firefighters crying. She breathes a sigh of relief when she sees
Jin-Woo is fine. She finally has an emotional breakdown and expresses how sirens scare her,
because she worries she will lose Jin-Woo to this extremely dangerous job. Suddenly their
walkie-talkies prompt a fire hazard. Jin-Woo has made a choice. He chooses his career over
his love. Soo-Jung stands there heartbroken. Hee-Chan is studying hard and getting good grades
at school. He doesn't want his mother to worry about him. One time while visiting his mother,
Hee-Chan wishes he was sick instead of her. The intensity of her emotions projects as she
raises her hand on her son. She is terrified of losing her son to the disease she has. Hee-Chan
is heavily influenced by his mother's journals. He is sitting on a swing, thinking about his mother,
when he sees Ha-Seok. Ha-Seok joins him on the swing. Hee-Chan is displeased with him because he
thinks Ha-Seok makes women cry. They have a hearty chat, most of which Hee-Chan doesn't understand.
As they go their way, Ha-Seok hands him his card in case he needs it in the future.
Jin-Woo comes to see Soo-Jung, but she doesn't want to see him. It is entertaining to watch
Jin-Woo trying to understand Soo-Eun. He thinks he understands what she is communicating through
sign language but always manages to get it wrong. Soo-Jung finally comes out of her room,
but she is in no mood to talk. Soo-Eun tries to reason out the situation, but Soo-Jung locks
herself in her room. She comes out, hearing Soo-Eun cry. Both of them watch a movie to
lighten their mood. While Soo-Eun is laughing while watching the movie, Soo-Jung tells her
the reason she wanted Jin-Woo to propose, to save him. She thought that once he was married to her,
he would think twice before jumping into the fire. But things didn't turn out in the way she wanted.
Even though her sister cannot hear her, she feels relieved getting this off her chest.
At school, Hee-Chan gets in trouble. The teacher calls his dad to let him know what happened. He
requests his dad not to say anything to his mom. While leaving the staff room, he overhears another
teacher saying his mother has cancer. Hee-Chan puts on a brave face and walks out. That innocent
boy doesn't know what cancer does, so he asks his classmate, whose dad is a doctor. She tells him
that people who have cancer die. Hee-Chan doesn't want to accept that he is going to lose his
mother. He is unusually quiet while walking to the bus stop after school, but his face lights up as
soon as he sees his mother on traffic duty. He is now sure his mother will be all right. They walk
back home hand in hand, brimming with joy. Ha-Seok diligently performs his duty as the
messenger of breakup. Addressing one such client, he visits her boyfriend. He gets beaten up by the
rowdy man, but Ha-Seok is far from giving up. He gets kicked, punched, and thrown things at,
but he doesn't give up. Just so he can deliver the message properly, he takes the fire extinguisher
and starts smashing it against the rowdy man's door but accidentally knocks him out.
Ha-Seok then runs away from there. He meets Suk-Hyun, and they both have dinner together.
Suk-Hyun wants to tell him something, but he interrupts her. She decides that would be a
conversation for some other time. Little does he know that he'll soon get a request from Suk-Hyun,
who wants to break up with him because she has found a new love. He cannot stop his tears as he
speaks it aloud to himself, looking at his reflection after he gets her request.
After a rescue operation, Jin-Woo is on a break with a fellow fighter man.
He tells a story about a fireman who jumped into a blazing building to save a girl. Against all odds,
they both survived. Unlike most romantic stories end, here, the fireman doesn't start dating her.
Instead, he ends up dating her sister. Soo-Jung comes to see him. They reconcile and share a
romantic kiss on a beautiful starry night. Soo-Eun finds Sang-Yun dosing off on a bench.
She sits next to him and removes her mascot mask. She looks at all the sketches he has made,
envisioning what the mascot girl looks like. When he wakes up, he finds her sitting with the mask on
next to him. Once again, he is deprived of seeing her face. The seven dwarf mascots and her friends
have been seeing this for a long time and decide to take action. They encourage her to stop hiding
and talk to the guy she has had a crush on for the longest time. This brings a smile to her face. She
wants to look beautiful when she meets Sang-Yun as herself. Her sister helps her get ready. The two
meet at the park, and Sang-Yun compliments her, saying she is more beautiful than he imagined.
She fulfills his wish of sketching her. He jokingly asks her whether she can't speak as
he is the one doing all the talking. But when she reveals that she indeed cannot speak, he is
flustered at his ignorance. He hands the sketch to Soo-Eun once he is done. Seeing herself from
the eyes of her crush makes her teary-eyed. She removes all her makeup and then asks Sang-Yun to
sketch her again. She wants him to see her as she is without any filters. He tells her that he will
be leaving the country to study abroad. He cannot bring himself to draw her. She very well knew this
would happen but didn't want to hear about it. So she puts the mascot's head on him and hugs him,
while trying to hold back her tears as she bids him goodbye. The world around them lights up.
Jin-Woo and his colleagues are having fun while washing their fire trucks. Once they are done,
Jin-Woo cleans up and is about to leave when he finds the ring he had brought for Soo-Jung.
He thinks it is time he gives it to the love of his life. The next day he is waiting for
Soo-Jung outside her office. She is surprised to see him. He has something to say to her
but saves it for later. In the evening he is waiting for her in a restaurant. He practices
his proposal before he asks her to marry him. Soo-Jung is reporting from the studio
when they get breaking news. A fire broke out in a shoe factory, eliminating two firemen,
one of whom turned out to be Jin-Woo. She suddenly stops at this revelation. It is heart-wrenching
to see the table still reserved for two with a bouquet of flowers, and champagne awaiting
the proposal that will never take place. Hee-Chan comes to the hospital to visit his
mom but sees her crying in pain. His dad is desperately trying to hold back his cries,
but seeing his wife die in front of his eyes is too much to take for him. Even in this tough time,
Hee-Chan thinks of his mom and how he doesn't want his mom to see them getting weak. He stands
outside in the rain and then cries his heart out. Ha-Seok visits Ju-Young in the hospital. He is
sent by Hee-Chan, who is his last client. Opposite to what Ha-Seok's work required him to do,
his last job request was to deliver the message that Hee-Chan doesn't want to be separated from
his mom. He wants his mom to get well and stand again. He then shows Ju-Young her portrait that
Hee-Chan made. She asks Ha-Seok to thank Hee-Chan for drawing her so well. With these parting words,
she succumbs to her illness. It is pouring hard that night as if
the sky is mourning with them over the loss of their loved ones.
Soo-Jung is called to the station to give the last of Jin-Woo's belongings. She finally gets
the ring he intended to give her. And a videotape showed his last moments where he gestures 'I love
you' in sign language and gets it right this time. Soo-Jung finally lets her emotions out.