Uwasa no Midori-kun!! Natsuiro Striker

Yamate Midori is a 15 year-old girl and is a tomboy. One day, Midori meets a boy called Hino Tsukasa, who came to the island she lives on for a holiday. He teaches her to play soccer and she falls in love with the sport. Inspired by Tsukasa, Midori continues to play soccer in hopes that they would meet again someday. When they do meet again, Tsukasa loses her trust by doing something unforgivable. Determined to defeat Tsukasa on the soccer field, Midori enrolls in an all-boys high school.

(Source: Wikipedia)