Renai no Susume

Otori Keisuke attends a prestigious high school that has implemented a rigid environment to allow students to focus on their studies only. The high school has a strict rule that all kinds of entertainment are banned, including dating. If a student is found to be dating, they will be expelled from the school. Otori Keisuke happens to meet a girl and falls in love for the first time in his life. He is not willing to give up on his first love and goes up against his school's rule on dating. His friends attending the same school try to stop him, but they become touched by his sincerity.
(Source: AsianWiki)