Natsu e no Tobira

The Door into Summer
Cover of the Anthology Book Natsu e no Tobira
夏への扉 (Natsu e no Tobira)
Genre	Drama, Romance
Manga
Written by	Keiko Takemiya
Published by	Hakusensha
Demographic	Shōjo
Magazine	Hana to Yume
Published	October 1975
Volumes	1
Anime film
Directed by	Mamoru Masaki Toshio Hirata
Written by	Masaki Tsuji
Studio	Toei Animation Madhouse
Released	March 20, 1981
Runtime	60 minutes

The Door into Summer (夏への扉,, Natsu e no Tobira^?) is a 1975 Japanese manga by Keiko Takemiya. It is an early example of a shōnen-ai manga. It was originally serialized in Hana to Yume, published by Hakusensha, and it was re-released in 2000 by Kodansha. An animated film version of this manga was released on March 20, 1981 in Japan.

The original manga of Natsue no Tobira is a short story, which first appeared in 19th and 20th issues of magazine Hana to Yume in October, 1975. This work was contained in the anthology book of Keiko Takemiya, published in 1976. In 1981, a 60-minute anime movie adaptation was released in Japan.