After punching a famous curator in the face for criticizing his work as "textbook and lifeless," Handa Seishuu is sent to Gotō Island to calm his nerves and find new inspiration for his calligraphy. Growing up in the city all his life, though, Handa must adapt to country life while meeting an assortment of quirky people during his tenure.

After a bus accident leaves high school student Yiyong in a coma for over a year, he awakens with his grandfather’s supernatural powers. His once ordinary life turns into a thrilling ghost-filled adventure alongside his school rival, Cao Guangyan, and rookie policewoman Chen Chuying.

Set six years prior to the events of Barakamon, detailing the life of Seishuu Handa as a high school student—and a very interesting life it is. In Handa-kun, Seishuu Handa is admired by his peers as a calligraphy genius and given the utmost respect, but Handa-kun himself is under the mistaken impression that the deference and attention he receives from the other students is actually bullying. Handa just wants to live a quiet life, but hilarity ensues as one character after another challenges his position as the school idol, and somehow comes away as a fan all while Handa is horrified and clueless.

A proud young calligrapher is punished for punching a critic by being sent to a faraway island in the east coast of Japan. But as he meets and lives with the island's friendly people, his attitude begins to improve.