Kosuke Mizushima stands up, all set to go to a wedding.
The bride in the wedding hall is Mana Hayase.
Kosuke relives his memories of the days gone by.
Ten years ago—
In a provincial city with a pleasant climate and beautiful landscape, Kosuke Mizushima (Yuki Yamada) is the only son of a small tofu shop owner and a high school senior prepping for college entrance exams. His life is happy and carefree, and he enjoys hanging out with classmates Junon (Keisuke Nakata), Kento (Naoki Kunishima), Ikki (Ryosuke Yusa), and Yohei (Takara Sakumoto). At school, he is labeled a troublemaker by the teachers, one of whom moves him to a desk right in front of Mana Hayase (Asuka Saito), a doctor’s daughter and the school’s top student. The teacher tells Mana to help him study and change his attitude, but Kosuke feels uncomfortable around the beautiful and serious Mana. The only thing he has in common with her is Utako Komatsubara (Honoka Matsumoto), Mana’s best friend and Kosuke’s childhood friend. But one day, a shift occurs in their relationship when Kosuke helps Mana stay out of trouble when she forgets her English textbook at home. As a sign of her gratitude, Mana prepares a small math test for Kosuke, hoping to improve his grades in his worst subject. Although Kosuke wants no part of it at first, he gives in to Mana’s relentlessness, and they start studying together in the morning before classes and in the afternoon after classes. Kosuke, who saw Mana as a no-nonsense model student, is surprised to see that she is quite charming and cheerful and doesn’t take herself so seriously. On the other hand, Mana learns that Kosuke is not just a silly prankster but is actually kind-hearted and is in a desperate search of himself. They slowly grow closer and closer. But Kosuke, who doesn’t know what he wants to do with his life, lacks the confidence to tell Mana how he feels about her. Then graduation day arrives. Mana moves to Tokyo for college, dreaming of becoming a doctor one day. After Kosuke sees her off, he moves into a dormitory of a local college…….