Kazuhisa Fukase graduated from a prestigious university, but he leads a boring life. His only strength is making delicious coffee. Whenever he makes coffee, he is reminded of his friend Yoshiki Hirosawa. He was friends with Yoshiki Hirosawa back in their university days, but Yoshiki Hirosawa died on a snowboarding trip 10 years ago.

One day, he meets Mihoko Ochi at a coffee shop. He is strongly attracted to her.

Kazuhisa Fukase goes to a professor’s retirement celebration at a university. There, he meets Kosuke Asai who went snowboarding with Yoshiki Hirosawa on that fateful trip. Journalist Toshio Ogasawara also appears there. He has been investigating Yoshiki Hirosawa's death.

With graduation 10 days away, homeroom teacher Hiiragi gathered all 29 students of class 3-A and proclaims them his hostages. His last lesson regards the death of a student that passed away a few months before. Nobody will be able to graduate until the truth is known.

High school student Moe has moved to a new town after the death of her father. Moe’s already having enough trouble fitting into her new class as it is, so she’s totally mortified when she ends up being “rescued” by local firefighter Kyosuke during a fire drill ... in front of all the kids at school. But the embarrassing incident might be a blessing in disguise, because gruff-but-kind Kyosuke gives Moe the courage she needs to leap out of her comfort zone as she aims to leave her loner days behind. Not to mention she’s soon falling head over heels for him … !

Students, including Aoi Nishino, take part in class and sports activity at a prestigious high school. Aoi Nishino is a member of the school's archery club. He practices archery studiously and doesn't socialize much with the other students. His childhood friend Haruka Seno is also a member of the archery club, but she worries about Aoi Nishino. One day, thunder strikes the school grounds. After that, the ordinary lives of the students changes drastically. Many samurai descend on the school grounds. It appears that the entire school has traveled back in time to the Sengoku period. Making things worse, they realize that they are in the time right before the Battle of Okehazama takes place.

Aoki has a crush on Hashimoto, the girl in the seat next to him in class. But he despairs when he borrows her eraser and sees she's written the name of another boy—Ida—on it. To make matters more confusing, Ida sees Aoki holding that very eraser and thinks Aoki has a crush on him!

With her gloomy demeanor, Sawako has a hard time fitting in. But when an outgoing classmate approaches her, life takes a turn for the better.