A lightweight romance with some funny moments, centred around three years of a university swim team. Ami is training to be a diver. She loves Hiroki who was her family's benefactor. He's young, rich and a champion swimmer. She hates Keisuke who is descended from a rival family (of bakers!!!). Keisuike resents Ami being standoffish, and he's not sure if he can overtake Hiroki on the podium.
"Rough" refers to a rough sketch, which shows the original intention but is filled in with more detail after time. After some major upheavals, Ami decides who she loves, Hiroki regains champion status and Keisuke makes some commitments. All before the final race....
The movie is well done, altho the goal wasn't very ambitious. For all the young bodies in swimsuits, it wasn't trying to be sexy. The focus was on growing up and opening up and (the big sports theme) TRYING. Some comic potential is ignored so as not to overshadow the romance.
At the time of writing this, the IMDb plot says this is a movie about a teenager's descent into a drug-fuelled hell. That's the wrong movie.