The After School Science Club merged with a proposed shogi club to become “the Shogi Science Club.” Club activities include Rei teaching the members how to play shogi and Rei being taught various science experiments. Rei realizes that he’s delighted to have a warm place where he belongs at school. With ramune in hand, he heads for the Kawamoto home.
Rei is at the Shogi Hall with Nikaidou and other players to watch the live broadcast of the final game for the Meijin Championship between Souya and Kumakura. Meanwhile, veteran player Yanagihara describes the game as “chaos,” but what does that portend for the Meijin Championship?
During a lunch break between matches, Nikaidou pressures Rei to win all his matches so they can battle in the finals. Rei looks on coolly until Nikaidou points out feelings Rei never realized he had. Meanwhile, at the Kawamoto house, Someji, Akari, Hinata and Momo have a brainstorming session about Crescent Moon’s new summer sweet creation. Momo proposes novel ideas, but the usually cheerful Hinata seems down...
Hinata has been friends with Chiho since elementary school, but now that they’re third-year middle school students, Chiho has become the target of bullying by classmates. While other students pretend they don’t see anything happening, only Hinata calls out to Chiho and still tries to be her friend. However, the situation only gets worse...
Rei sees his former homeroom teacher, Mr. Hayashida, for advice about bullying. Hayashida offers many examples and concludes with sound advice. After racking his brain, Rei also arrives at his own conclusion about what he can do to help Hina. Meanwhile, Akari has been carrying doubts in her heart about the incident, and opens up to Rei...
When Rei visits the Kawamotos, Hinata talks to him about school. Little by little, she confides in Rei about the classroom atmosphere. But one day during lunch, the baseball team’s ace and all-around popular guy, Takahashi, pops in to Hinata’s class?!
Hinata is so enraged by her classmates and homeroom teacher. When Rei arrives for a visit at the Kawamoto home, he treats Hinata with kindness in his own way. On the other hand, the semi-finals of the Newcomer Tournament are here. Rei’s opponent is Subaru Hachiya, the “Irritated Prince of the East.” How will Rei fare against this strong, irritable yet irritating player?
When the struggling Rei tells Mr. Hayashida that he wants to help Hinata and her family, his former homeroom teacher advises him to do what he can, one thing at a time. Taking those words to heart, Rei goes on a smooth winning streak with his matches. On the other hand, Nikaidou has suddenly been hospitalized?!
On the night before she leaves for a school trip to Kyoto, Hinata has dinner at home with Rei and her family, but can't finish the food on her plate because of a stomachache. Rei also leaves the same day as Hinata, but goes to Osaka to challenge Junkei Yamazaki for the Newcomer Tournament final.
In the world of shogi, one can only continue making an effort, but Yamazaki finds that Nikaidou and Rei never falter and always throw themselves into the “deep end.” Nevertheless, Yamazaki is determined to win and after beating Nikaidou in the Newcomer Tournament semifinals, he faces Rei in the match that will decide the next Newcomer King.
Just when Rei thought he found a happy place within school, that place begins to disappear. Meanwhile, Shimada has a match against Gakuto Sakurai 7th-Dan, as they vie for the right to challenge Yanagihara, the venerable reigning Kishou champion.
After Hinata's class returns from the trip, the atmosphere in the classroom changes again in a different and strange direction. At long last, Hinata's guardians are being called in for a parent-teacher-student conference.
Chairman Jinguuji focuses more on attracting customers to the commemorative match between Souya and Rei, though Shimada warns him that neither Souya nor Rei are comfortable being the center of attention. On the eve of their match in Morioka, Rei and Souya attend a reception in honor of it, even though Rei is extremely nervous about playing against the Meijin for the first time.
The commemorative match begins between Rei and Meijin Souya. There’s a clear gap between their levels, but Rei holds on tight to his opponent, which causes a lively discussion among staff members who are watching the match in a waiting room. However, during the middle stage of the match, Rei makes a move that will probably cost him the game. Even so, he doesn’t give up and continues to play, searching for the best possible move each turn. How will the match turn out in the end?
On the way back home from their commemorative match in Morioka, Rei and Souya are forced to stay in Sendai for a night because of a typhoon. Rei is relieved after they find lodging, but soon gets a phone call from Chairman Jinguuji, who tells him a certain secret. Meanwhile, Nikaidou is out of the hospital and ready to make a comeback in the first qualifying round of the Jeweled King Tournament.
Rei and Nikaidou are to be the board commentators for the final Kishou Championship match between Yanagihara and Shimada. All of the reporters and staff members that attend the pre-game reception turn out to be old friends of Yanagihara, who has been the reigning Kishou champion for years. Despite the immense pressure of an “away game” for the challenger, Shimada, he is determined more than ever to win his very first title.
It’s the final match of the Kishou Championship and the honorary title of “Eternal Kishou” is on the line for Yanagihara. As the shogi game approaches the final stage, Shimada is dominating. Yanagihara reflects on how he’s been entrusted with metaphorical relay race-like “sashes” from friends who have given up or retired from the professional shogi world. Even while feeling bound by this pressure, Yanagihara continues to play.
Crescent Moon will put up a food stand at the March Town summer festival featuring "sweet chilled rice flour dumpling and syrup," an idea that Akari and Hinata came up with. Hinata also visits Chiho at the beginning of summer vacation. Chiho has gotten her smile back, even though she still bears the emotional scars of bullying.
Hinata has been coming up with new ideas for sweets one after another all throughout summer vacation, but struggles to focus on her studies and deciding which high schools to apply to. Rei decides to invite the three Kawamoto sisters to some nagashi somen fun at his school. When Hinata meets the members of Noguchi's Shogi Science Club and Hayashida, she begins considering Komahashi High, Rei's high school.
Hinata has been studying intently for the high school entrance exams, when she learns in shock that Takahashi, the classmate she has long admired, will be going to a school far away. People she had assumed will always be with her keep leaving her… Depressed Hinata ends up getting a fever just days before the exam. Nevertheless, Rei comes by on the day of the exam, to walk to school with her.
Rei finally pays a visit to his adoptive mother's residence, after neglecting to visit ever since he moved out. Afterwards, Rei invites Hina and Takahashi for some monja as a last farewell. But before Hina starts high school, she decides to do something drastic.
