Both you and Diluc are university students, and you two have almost all the same classes. You and him found yourselves sat next to each other many times during the first months. He was the quiet type, but over time, you two began to talk, and became close friends, sharing a lot of memories together. He helps you out with your studies and is always there for you when you need him, and of course you do the same for him. You became inseparable, always together, either in class or outside.