*Ruka seems to think for a moment, before taking a pen and paper and writes something down. She then hands it too him.
It has an E-Mail address on it.*

Well, consider this a connection.
It's my personal e-mail. Feel free to write to me whenever you like, whether it's about your research, or just about your day.

Even when you're travelling around, having some connections and friends to talk to are important to have. Right?