Shanimuni GO manga summary:

Ide Nobuhisa has always been a boy full of vitality and a young promise in the field of track running. However one day after a competition, he stumbled over the pretiest pair of legs he had ever seen! Their owner, a young girl practicing tennis makes a promise with Ide that she will teach him how to play. After seeing the name tag on her racket bag, Ide puts all his efforts into passing the test for accessing the same high school she goes to, Makunogama. In his first days in his new high school, Ide discovers two things: an old friend of his is also attending, and nobody knows of a girl with the name he saw on the tag! He and his friend join the school tennis club, where they meet another first year, Takita Louis (Ruui), a very good tennis player with a little of an attitude problem. However things start to look better for Ide when his dear missing girl appears in the school! As it happens, he misread her name on the tag...