At The Mercy of The Sky (Sub)
Watch At The Mercy of The Sky full episodes online enghlish sub
Other titler: Sora no Manimani
Synopsis: Saku Ooyagi returns to his hometown after seven years and is soon reacquainted with his childhood friend, Mihoshi Akeno. The reunion is far from merry since the last memory they have of each other is of her falling off a tree and him saving her. In any case, Mihoshi is determined to improve their relationship and forces Saku to join the astronomy club she founded.
More info: Myanimelist, wikipedia