Tomoya, Nagisa, and Youhei finally find out that Yukine is respected by the two rival gangs in the city since she helps both sides' members after they get hurt. Her older brother is the leader of one of the gangs, and a young boy named Yu comes to her to find his older sister who apparently is dating a guy in Yukine's brother's gang. Youhei tells Yu that he is Yukine's brother for a time, but the truth is later revealed after Yukine takes Yu, along with Tomoya, Nagisa, and Youhei, to a bar where her brother's gang hangs out. Yukine's brother has been in the hospital since he saved a friend and got in a car accident. While heading home, three members of the rival gang think Youhei is Yukine's brother and try to fight him and Tomoya, but Tomoyo intervenes, stopping them single-handedly.

After the previous night's events, Tomoya goes to see if Nagisa is okay, and finds out that she has been physically weak all her life. While walking back from the bakery, Tomoya helps get a strange electrician out of a jam and he gives Tomoya his card, finding his name to be Yusuke Yoshino; Youhei later reveals that Yusuke is a retired professional musician. After school the next day, Tomoya helps Nagisa get more self-confidence for the drama club by acting as a new member of the club asking questions.

In order to help Fuko out, Tomoya and Nagisa take her to stay at Nagisa's house for the time being. Nagisa's family helps with carving more starfish out of wood, and at school Tomoya and Nagisa help with passing them out to students. Later, Fuko talks about how she has wanted to attend classes, but has never been able to. Tomoya makes arrangements with Youhei, Kyou, and Ryou to act as classmates in Fuko's very first high school class, and even Sanae comes to act as the teacher.

Since no new members have joined the drama club, Tomoya goes to talk with Kotomi once again about joining. Tomoya takes her around school and helps her introduce herself to people to make more friends. Tomoya takes Kyou, Ryou, and Kotomi to the drama room after school, and after a round of introductions, Tomoya asks them to join the club. Kyou initially passes on the chance, but ends up giving in after her sister says she wants to join, and Kotomi joins as well. During the meeting, Kotomi leaves when she hears someone playing the violin, though when she is given the chance to play it, she is painfully horrible.

On the way to school one day, Tomoya Okazaki meets a strange girl talking to herself named Nagisa Furukawa. Later in the day, Tomoya has a conversation with Nagisa during lunch and learns that she is repeating her last year of high school, and wants to join the now-disbanded drama club. After school, Tomoya goes to Nagisa's family bakery and meets her parents; he is invited to have dinner with them.

Nagisa admits to wanting to restart the drama club, and Tomoya helps Nagisa to create advertisement posters which they place around school. At school that day, Tomoya meets two other girls: a strange genius named Kotomi Ichinose, and a first-year named Fuko Ibuki. Later that day, Nagisa finds out Tomoya used to play basketball, and invites him to play a game the next day. However, it is later revealed that his father injured Tomoya's arm in a fight; as a result, he is unable to play basketball anymore.

Tomoya and Nagisa invite Fuko's older sister Kouko to the Founder's Festival. In the meantime, Fuko hands out more carved starfish to students at the festival, and her fan club helps spread the word about Kouko's wedding too. Nagisa and Tomoya meet Tomoyo, who is wearing a bear suit to find people who are causing trouble, and manages to knock Youhei out a window for bothering a girl. When Kouko finally comes, she cannot see or hear her sister.

Kotomi is still trying to play the violin, but has not improved at all; in short, her playing is painful to anyone listening. Kyou gets the idea to have Kotomi play at her first violin recital after school the day after tomorrow, and in the mean time Kotomi can practice. The day before the recital, Tomoya visits Kotomi at the school's library and eats her delicious homemade apple pie. Shortly after, Tomoya falls asleep and has a very strange dream. At the recital, Kyou blackmails several students into coming with her position as a class representative. In the end, Kotomi did not improve at all, and the recital was still very painful to listen to. When Kotomi and her friends are going home, a strange man approaches Kotomi, though leaves shortly after; Kotomi was terrified of him

In order to help Nagisa reform the drama club, her friends offer their names in order to get enough members to qualify, but they still need a teacher to advice them with the club, which leads them to ask Toshio Koumura. However, he is already meant to be the adviser for the choir club, so Nagisa goes to talk with Rie Nishina about which club Koumura should advise. The next day, Nagisa finds a threatening letter in her desk, and Youhei finds out that it was Rie's friend Sugisaka who is behind it. After talking with Nagisa about Rie's past, Nagisa chooses to give up on reforming the drama club, though this does not sit well with Youhei. Tomoya and Youhei go to Yukine Miyazawa to kill time during school, and Yukine gives Youhei an idea related to basketball. The next day, Youhei approaches Tomoya and Nagisa about playing in a basketball match in order to get the choir club to back down, but Tomoya continuously refuses his offer.

Yohei and Sanae go out on a date, accompanied by Mei, Tomoya and Nagisa. During the date the group witnesses a young girl being bullied by some slightly older boys. The scene is resolved by the girls older brother rushing in to help his sister. Mei remembers how Yohei used to be like that, but once he joined the football club he didn't seem to care about her any more. The group then tries to provoke a brotherly response from Yohei, to get him to stand up for his sister; Tomoya pretends to be romantically interested in Mei, but despite being shocked, Yohei doesn't say anything to oppose them. Mei decides to stay a little while longer, as she can't leave things the way that they are.

Tomoya runs into Fuko again at school, and she tries to invite him to her older sister's upcoming marriage ceremony, but Tomoya is not interested. Tomoya gets Youhei to help reform the drama club by bribing him with bread from Nagisa's family bakery. Nagisa tries to get the help of Ryou and Kyou in reforming the drama club, and Tomoya even tries to ask Tomoyo and Kotomi if they would like to join; Tomoyo is trying to become student council president, and Kotomi does not give an answer. Tomoya and Nagisa later go see Fuko about the club, and he discovers from Nagisa that Fuko is supposedly unconscious in a hospital.

Tomoya and Nagisa visit Youhei, and spend some time talking with Misae and Tomoyo who comes over after them. Later, when Tomoya and Nagisa are talking with Misae privately, Tomoya starts falling asleep. It is shown how when Misae was a first-year in high school, she met a strange boy named Katsuki Shima who says he can grant her one wish in return for her cheering him up years before when he was in the hospital. Misae has a boy she likes named Igarashi, but who unknown to her already has a girlfriend. Igarashi asks Katsuki to tell her this, but he cannot tell her directly and starts crying. Misae sees Igarashi with his girlfriend, and realizes the truth; she runs away, leaving Katsuki behind.

Tomoyo speaks to Yukine and the others about hearing that the police will start to get involved in the fight between the two gangs if it gets any worse. Trying to stave off a major brawl, Yukine goes with Tomoya to try to talk the other gang out of a fight, and the leader settles on a fight between him and Yukine's brother Kazuto. Youhei reluctantly goes to stand in for Kazuto, but is incapacitated along with everyone else but Tomoya after eating Sanae's bread, so Tomoya fights the leader of the opposing gang. Yukine impersonates Kazuto to end the fighting, and finally reveals to everyone that did not already know that Kazuto has been dead for some time, and his wish was to end the fighting in the town. At the cemetery, Yukine pays respect to her dead brother and the rival gang joins in. With the rivalry resolved and peace restored, Tomoya witnesses a glow rising into the sky.

Kotomi returns the violin to Rie Nishina and becomes friends with her. Kotomi changes her usual routine and starts attending her classes. Due to Kyou's idea, she, Ryou, Kotomi, Nagisa, and Tomoya go out together as a group and have fun in town. While out, Fuko makes an appearance in, but no one remembers her. The next day, Nagisa runs up to Kyou thinking Ryou got in a bus accident, though when they rush to the scene, they find no one was hurt; however, Kotomi has an emotional episode and collapses while screaming out. Kotomi leaves early that day, but when Tomoya, Nagisa and the Fujibayashi twins go to see her later, there is no answer at her house. After they leave, Tomoya goes back and runs into the strange man from earlier; he finds out the man is an acquaintance of Kotomi's parents.

Summer vacation is now over and the second semester has started at Tomoya's school. Nagisa's father Akio asks Tomoya to form a baseball team for a local game against the neighboring shopping district team. Tomoya is able to recruit Kyou and Kotomi from the drama club, Youhei and his younger sister Mei, Tomoyo, Misae, and Yusuke. Tomoya's team manages to get an early lead, but Akio's leg gets injured by a flying bat, and Nagisa fills in for her father as the pitcher. The other team catches up near the end, and it comes down to the final inning when Tomoya scores an RBI, winning the game.

Mei has become worried about her older brother since he still does not have a plan after high school, and comes to stay at Nagisa's for the time being. Based on a fleeting comment by Youhei, Tomoya gets the idea to ask a girl to pose as his girlfriend so Mei will stop worrying about him. Youhei goes around with Tomoya and Nagisa asking Ryou, Tomoyo, Kotomi, and Yukine, but no one can help him. Sanae overhears Youhei's trouble and decides to be his fake girlfriend if it will help push him in the right direction in life. Youhei, however, still believes her to be Nagisa's older sister. When Mei meets her brother's "girlfriend", Sanae is posing as a student from Tomoya's high school.

Tomoya and Nagisa convince Kouko that Fuko would wish for her to get married despite Fuko's condition. They talk to the school's administration after finding out Kouko would like to get married on the school grounds. Kouko informs them that Fuko's condition has gotten worse, and she may not awaken from her coma, while Youhei shares his observation that some students cannot see Fuko and others are beginning to forget her and the presents she gave them.

More people from school are not able to see Fuko anymore and now even those close to Fuko in the past are beginning to forget about her. First Youhei forget after he goes to see her in the hospital, followed by Kyou and Ryou. Tomoyo manages to remember with Tomoya's help however. Later, Youhei manages to remember Fuko for a moment, but is unable to remember any more. Tomoya and Nagisa buy Fuko a birthday party set to cheer her up. When they get back to the bakery, they discover that Nagisa's father has forgotten Fuko, and while Nagisa's mother has not forgotten completely, she cannot see her anymore. Tomoya and Nagisa decide to take Fuko back to school for now.

When Mei shows up, she cleans her brother's filthy room, but cannot stay at her Youhei's all-boy dorm, so Nagisa offers to have her stay at her home while she is in town. Tomoya and Youhei easily get Kyou to help with the basketball game, and she gets pumped up after a comment about pairing up with such loser guys. For half the game, Tomoya and the others play against first-year rookies, and manage to lead by eleven points, but then the basketball team switches with their starters and the score evens out. In the very last seconds of the game, Tomoya manages to make the last shot and win the game. Afterwards, Mei goes back to her hometown.

After watching the basketball game, the choir club decides to share Koumura with the drama club, but the student council will not allow it. Nagisa collapses at school and cannot come to school for a few days. During this time, Tomoyo starts waking up Tomoya and Youhei before classes start so they will not be late anymore. Kyou continues to set up situations where Tomoya and Ryou are together, such as eating lunch together. Yukine tries to help Tomoya with a charm book, and he performs a charm to get locked in the gym equipment room with Kyou, which ends up happening. Kyou does not act like her usual self while in the room, and thinks that Tomoya may end up trying to have sex with her. Tomoya undoes the charm and the door is opened by one of Kyou's classmates. Tomoya and Tomoyo start to walk home after school, but a a bunch of gang members are at the school's entrance looking to fight Tomoyo.

The drama club is finally re-established and Koumura is shared with the choir club. Tomoya's home room teacher goes to Tomoya's house to ask his father about his future, but Tomoya's father says that is something that Tomoya has to decide for himself. Seeing the strained relationship between Tomoya and his father, Nagisa offers to have Tomoya stay over at her house for the time being, which he accepts. After coming home from school, Tomoya finds several small kids in Nagisa's house, and finds out Sanae is instructing them in a cram school. Nagisa confides to Tomoya that she feels she did something really bad to her parents in the past, but she cannot remember what it is, and her parents say that she must be imagining it.

Nagisa and her friends continue to practice for the play, such as reciting tounge twisters, choosing which music to use for the play, lighting, and stage direction. Nagisa's father rents a play on video, and Nagisa finds it very touching, plus it was the first play she ever saw. Tomoya and Akio try to find the script of the play that Nagisa is going to perform in the shed, but do not find it. The drama club has a practice the day before the school festival is to begin and it goes well. The night before the school festival, Nagisa looks for a flashlight in the shed, but bumps into some boxes and discovers photographs and diaries of her parent's pasts.

Tomoya realizes that he met Kotomi as a kid, though only she had remembered. Back then, Tomoya had often visited Kotomi, and was her only friend. Around this time on Kotomi's birthday, her parents left for business reasons, and later that day she finds out they were killed in a plane crash. Kotomi ultimately ended up burning her father's important work before anyone could see it. While Kotomi shuts herself in her house, Tomoya comes over and starts cleaning up the garden which is overgrown with grass and weeds. Nagisa, Kyou and Ryou eventually help out too.

Working has its ups and downs for Tomoya. He does not want his boss to find out that he has an injured shoulder, in fear that he will lose his new job. He promises Nagisa that he will join her at the Founder's Festival, yet work gets busy and while his fellow co-workers would have covered for him, he wanted to prove his worth. He is late for his date, and is starting to become too busy to sustain a healthy relationship with Nagisa. He gains respect with his co-workers and settles into his job.

Shortly after his graduation, Tomoya decides to be more independent, and works toward this goal by first taking up a job at the bakery. Meanwhile, Nagisa has begun her new school year, although she makes few friends and her attempt to reestablish the theater club ends in failure. Tomoya eventually moves out of Nagisa's home to a small apartment of his own, while taking up a job as an electrician with Yusuke Yoshino. After his first day of work, Tomoya returns to his home completely exhausted, barely able to stay awake during his dinner with Nagisa.