"Hatsune Island" (original Japanese name: DC ~ダ?カーポ~, referred to as D.C.) is a love adventure game developed by CIRCUS and officially released on June 28, 2002.

The story takes place on Hatsune Island, a crescent-shaped island famous for its magically blooming cherry blossoms all year round.

The protagonist, Junichi Asakura, attends Kazami Academy on the island. He has the strange ability to see other people's dreams while sleeping, and he can also use abilities taught by the magician grandma. A little magic to create snacks.

This time, Junichi saw the "sister" he had been with in childhood again in his dream, but he couldn't remember her name...

Unfortunately, Junichi Kazuichi's sweet dream was soon interrupted by his sister Nemu's prank, but facing such a cute sister Junichi, he couldn't remember it. Before going to school, Junichi insisted on taking her sister's temperature...

Actually, Junichi and Nemu were not really siblings. Junichi's family adopted Nemu when she was very young. Junichi takes good care of Nemu, making it seem like they are a couple.

When they arrived at school, Junichi and the others met the school's heartthrob idol Shirakawa Yuki, and Nemu's good friend Miharu. However, since it was the first day of school, a transfer student came to the school. She turned out to be the sister Junichi saw in his dream - Yoshino Yoshino. The appearance of Yoshino Yuki made Junichi panic at first, and Nemu felt a little uncomfortable.

Junichi's panic was right, Yoshino said: "I'm here to fulfill the agreement with my brother!" However, Yoshino's fiery enthusiasm made Junichi want to escape...

The matter was not over yet. At night, Yoshino actually climbed into Junichi's room through the window. Helpless Junichi tried to use magic to change snacks to distract Yoshino Yoshino's energy, but when Yoshino was not paying attention, Junichi kissed Junichi... All of this happened to be seen by Nemu who pushed in the door, and Nemu became angry. The ground rushed out of the door...