- "You're nothing but a collection of atomic particles. Does that make you more special than me?"
- — Rin —
Rin appears as a handsome youth with butterfly wings and amber colored eyes. However his original form was that of a caterpillar. He transformed into his current form after going through a sort of cocoon phase, just like a real butterfly. In his human form he wears a simple white robe.
Rin is a very considerate and caring person. He wants to live in a world where humans and AIs can live in peace, but realizes that most people see him as nothing more than bugged data. Despite his young age, he is very knowledgeable about both science and history. He's very close to the player Yukino, who raised him from his original form.
He was found by the player Yukino as a caterpillar, and she cared for him as he wove a cacoon and transformed into a human-butterly hybrid. The two met frequently, but they were eventually discovered by Kamui, the leader of The World's Debug team. Rin tried to convince Kamui not to delete him, saying that his existence had just as much worth as hers but it was a futile effort. Despite Yukino's protest Rin was deleted, but not before having a deep effect on Kamui.
- Rin is sometimes referred to as "Lin", this is not an incorrect name as L and R are interchangeable in Japanese. However his generally accepted name is "Rin".