In Burn the House Down, Kiichi Mitarai, played by Asuka Kudo, is the first person to discover Anzu’s identity when she comes to work at the Mitarai residence and decides to help her prove her mother’s innocence.
When Kiichi and Anzu were teenagers, their mothers were friends, and so the two of them used to meet each other often. Anzu liked Kiichi because he was smart and kind. However, after the fire incident, Anzu’s parents got divorced, and Kiichi’s mother married Anzu’s father.
13 years later, Anzu returns to the Mitarai residence as Shizuka Yamauchi in the hope of finding out who was responsible for the fire that ruined her mother’s life. The Kiichi that Anzu now meets is nothing like the boy she admired so much.
After marrying Osamu, Makiko did not want Kiichi’s old friends, a group of delinquents, around him. She paid them to stay away from Kiichi. As a result, when a bully cornered Kiichi and stole his money, none of his friends came to his rescue.
Kiichi’s life as a high school student changed completely. He no longer had friends and felt isolated. He spent all his time studying, as he wished to get into Teimei, a prestigious institution, and he succeeded on his first try.
Soon after, the news got out that Kiichi got admission because of his parents’ donation to the school. When Kiichi questioned Makiko about it, she admitted that she donated the money because she was not sure if he will be able to get admission on his own.
This led to Kiichi dropping out. As Kiichi’s name and face were everywhere on the internet, he stopped going out of his house because he felt he was constantly being watched by people.
Years later, Kiichi still stays locked in his room while his mother lies to everyone about him working for a trading company and living abroad.
A changed person
When Anzu comes to work for Makiko, she is asked not to go upstairs to prevent her from finding out about Kiichi. Anzu disobeys Makiko and comes face to face with Kiichi.
Initially, she thinks it is Shinji who lives upstairs, as she cannot imagine Kiichi living a life like this. She soon realizes that the man is Kiichi and decides to get him to like her by feeding him. She hopes that he will offer to show her around, which would give her the opportunity to find evidence against Makiko.
She thinks she is fooling Kiichi when in fact it is Kiichi who is fooling her. He has been suspicious of her from the very beginning because she knew all his interests. He gets her fired by ripping off a button from her apron and using it to show Makiko that she disobeyed her.
When Anzu gets her job back and returns, he hides a camera in his mother’s closet to catch Anzu red-handed. He figures out that she is Anzu Mitarai and records a video of her going through his mother’s belongings.
He uses this video to blackmail her. He makes her work for him, but not without Anzu pointing out that his work is meaningless. Although Kiichi does not come out of his room, he makes a lot of money on the internet by spreading false rumors about celebrities, including his mother.
When his mother finds out about his websites, he is forced to shut them down. He feels useless again and fights with Anzu, which leads to Anzu admitting that she is here because she thinks Makiko started the fire 13 years ago.
Kiichi has also suspected his mother for years; he even questioned her about it, but she made him promise that he will keep this between them. The incident has been haunting Kiichi for years, and he has come to hate his mother.
Kiichi’s second chance
Kiichi joins hands with Anzu to help her prove her mother’s innocence. For that, he even steps out of his house with her. When he fails to make progress and gets discouraged, Anzu pushes him to get his life together.
Kiichi knows that he has himself to blame for how his life turned out, and he takes responsibility for it. Anzu’s arrival is the push that he needed to try and turn his life around.
Anzu tells him that she liked him when they were young and that she still thinks that he is wonderful. She asks him not to give up and to be kind to himself. Kiichi then starts doing chores at home and learns to cook.
He also gives Anzu the idea to set up a trap for his mother, which works. His mother has no choice but to confess that she committed arson. Kiichi realizes that he cannot live like this anymore and leaves his family.
Anzu finds him and lets him stay with her. He confesses that he does not care about anyone’s opinion but hers, and it becomes evident that they like each other. He even takes her out on a date to show her the stars, the way he used to do when they were young.
However, when the police start investigating the fire incident again, Kiichi takes the blame for it. It turns out that he has known that his brother, Shinji, was the real culprit all these years. However, he could not let his brother or mother go to prison for this, so he took the blame.
The truth comes to light eventually, and the police let Kiichi go. Anzu then confesses her love to him, and Kiichi, who feels the same, decides to start life afresh with her. He gets a job, lives with Anzu, and is no longer the man who considered himself good-for-nothing.