Sainam Luk Phuchai

The story revolves around the friendship between Tan and his best friend Chucky. Both fall in love with Meen, who has been close with Chucky since childhood, but she likes Tan. From friends, Tan and Chucky become competitors - in love and also when they are named for the national swimmer team.
(Source: th.wikipedia; edited by msbrightside on MDL)