Hotarubi no Mori E (蛍火の杜へ, lit. Into the Forest of Fireflies' Light) is a one-shot shoujo manga written by Yuki Midorikawa. It was published in the July 2002 issue of LaLa DX in Japan, and in July 2003 it was reprinted in a tankōbon short story collection of the same name, which included four romantic one-shot stories written by Midorikawa.

Hotarubi no Mori e tells the story of a young girl named Hotaru and her friendship with Gin, a strange young man wearing a mask, who she meets at the age of six in a mountain forest near her grandfather's country home. Hotaru learns that her friend is supernatural and that touching Gin will cause him to disappear forever. Hotaru returns every summer to spend time with Gin, and their relationship matures as both struggle with its limitations. The inspiration to write the story came suddenly to Midorikawa, who immediately drew the manga—a process that went smoothly despite some initial conflicting elements. Hotarubi no Mori e is considered a starting point for Midorikawa's best known work, Natsume's Book of Friends.

A 44-minute anime film with the same title was produced in 2011 at the anime studio Brain's Base and directed by Takahiro Omori. The film starred Japanese voice actors Ayane Sakura and Kōki Uchiyama, and its soundtrack included music by Makoto Yoshimori. The film maintained a strong following for months in Japan after its opening on September 17, 2011. The European premiere of Hotarubi no Mori e was on October 8, 2011 at the Scotland Loves Animation festival, where it won the Jury Prize. It was screened at the Leeds International Film Festival, Anime Contents Expo and Anime Expo convention, and also won the Animation Film Award at the 66th Annual Mainichi Film Awards.

# Image Title Release Date ISBN
Hotarubi no Mori e (manga cover)
Hotarubi no Mori e (蛍火の杜へ) July 10, 2003 ISBN 978-4-592-17890-3

As part of the tankōbon collection, each of the four one-shot stories were set in a different season: Hanauta Nagaruru in spring, Hotarubi no Mori e in summer, Kurukuru Ochiba in fall, and Hibi Fukaku in winter. Within the tankōbon, the stories were arranged in order from spring to winter, although they were originally published in a different order.
Hotarubi no Mori e (manga cover)
Aizoban Hotarubi no Mori e (愛蔵版 蛍火の杜へ) September 5, 2011 ISBN 978-4-592-19840-6

  • Story 1: Hotarubi no Mori e (蛍火の杜へ)
  • Story 2: Taion no Kakera (体温のかけら)
  • Story 3: Hoshi mo Mienai (星も見えない)
  • Story 4: Hotarubi no Mori e Tokubetsuhen (蛍火の杜へ 特別編)
On September 5, 2011, 12 days prior to the anime movie's premiere in Japan, a new story related to Hotarubi no Mori e was published as part of a keepsake edition of the original manga, titled Aizoban Hotarubi no Mori e, 愛蔵版 蛍火の杜へ. The 12-page story, titled Hotarubi no Mori e Tokubetsuhen, 蛍火の杜へ 特別編, is one of four short stories included in the keepsake edition, which also includes the original Hotarubi no Mori e and two other older works by Midorikawa: Taion no Kakera, 体温のかけら (2003) and Hoshi mo Mienai, 星も見えない