The creator, Jin Kobayashi, has announced in the latest edition of Monthly Gangan Joker magazine that the final chapter of this great science fiction and romance story will come out on September 22.
The author, also known for School Rumble, will work on another story for Kodansha, but hasn't specified details yet, there's not even information on the name or the theme.
Natsu no Arashi! is the story of a boy named Hajime Yasaka, who meets an older high school girl named Sayoko, in a coffee shop. The girl, whose surname is "Arashi", reveals her secret during one fateful summer vacation.
The manga chapter started to come out on 2006, with an ongoing series that had its 2009 anime being simulcasted on Crunchyroll for audiences worldwide.