1x15 - Play It Cool, Guys

Shun gets a letter from a younger girl at school. After opening it, he realizes that it's a love letter and is about to immediately reject her when his friends stop him. Instead, they convince him to write a letter back. But since he has never really written a letter, let alone a response to a love letter, he agonizes over what to write. So he asks Hayate, Takayuki, and Souma for advice, but none of them are particularly helpful...