Board Thread:Questions and Answers/@comment-75.18.255.142-20140613090548/@comment-79.207.9.52-20170227115947

Actually, Yuzuru clearly used the word "aishiteru" twice when confessing his love to Kanade. This japanese term for "I love you" is exclusively used to express romantic love between lovers and couples. It's such a strong and meaningful term that it's rarely used, even between married couples.

In japan you will never use "aishiteru" to say "I love you" to a friend or family member like you do in the western world and english language. So no, there is no room for interpretation here, Yuzuru's love for Kanade is as a matter of fact of romantic nature.