Lake Haruna

 is a caldera lake. It lies near the summit of Mount Haruna, within the city limits of Takasaki, Gunma Prefecture, Japan. A former name for the lake is .
In the summer, the lake is a popular destination for campers. The surface freezes in the winter, and it affords skating and ice fishing for "wakasagi".
The lake lies a 90-minute bus ride from Takasaki Station. It can be reached in 40 minutes by car from Shibukawa-Ikaho Interchange, #12 on the Kan-Etsu Expressway.
A "kayōkyoku" refers to the lake in its title. Akira Fuse recorded the tune, named "Haruna-ko no shōjo". The music is by Rei Nakanishi and the lyrics by Ken'ichirō Morioka.
Parts of the anime and manga Initial D take place on or around the lake, under the fictional name Lake Akina, as Mount Haruna - named Akina (秋名) in the series - is the location of the tōge where Takumi, the protagonist, wins his first races.
Sources.
This article incorporates material from the article ("Harunako") in the Japanese Wikipedia, retrieved on March 21, 2008.