As I first step into the Shinigami realm I start asking every Shinigami I could find where I could find this Ryuk. Many of them are surprised to see an Arbiter walk around the Shinigami realm, but seeing as how I showed a keen interest to meet the Shinigami who I hear has quite a fascinating story about the Death Note he gave the human, they weren't so surprised after all.
One day a Shinigami named Sidoh tells me where I could find Ryuk.
Nona: So where can I find this Shinigami Ryuk, Shinigami?
Sidoh: The name is Sidoh madam. It seems like everyone has been asking about him these days. Aren't you an Arbiter by the way? I haven't seen your kind floating around here.
Nona: I came here only for the Shinigami Ryuk so I can talk to him.
Sidoh: You want to hear his story don't you? This may catch you by surprise but I was actually involved in what happened at some point. Not too deeply really. Like I did play a hand much later on from what I understand now as Ryuk told me, but of course he was the one who saw everything happen every step of the way.
Nona: You were there when this human was doing all the mass killings of all these people?
Sidoh: Oh yeah, they called that human "Kira." That's what the humans called him. Many of them came to worship him as their "god."
Nona: This is so interesting. I must know more! Where can I find Ryuk, you must tell me!
Sidoh: No worries. I think Ryuk now resides south of here. About two miles from here. Just keep walking in that direction and you should see him. He still keeps to himself even after everything he experienced. I must say, Ryuk truly is the strangest Shinigami I have ever known.
I thanked Sidoh and continued to walk along just as he told me. After walking about two miles I saw a new Shinigami. It seems that Sidoh was right after all. Could this be the Shinigami I was looking for?
Nona: Shinigami, I am an Arbiter from the Arbiter realm. My name is Nona. Is your name Ryuk?
Ryuk: Huh? An Arbiter has come down here to see me?
Nona: So it is you! Oh I am so pleased to finally meet you!
Ryuk: You're an Arbiter who came to the crappy Shinigami realm just to meet me? Wow Light our time together really has led me to becoming famous it seems!
Nona: I have been hearing of your fame Shinigami and from what little I have heard I must say I am already impressed. The human you attached yourself to called himself Kira? And is it true that people worshipped him as their god?
Ryuk: Oh yeah, Light was a real genius. The whole Kira phenomenon and investigation kept humans quite busy for years hehehehe.
Nona: So it is true then. And you personally knew him throughout all of this it seems, that's amazing. Shinigami Ryuk I would like to hear your tale.
Ryuk tells Nona the story of Light's rise to power as Kira. She would stop him at certain exciting points when things were getting edgy between Light and L. She gasped when she heard the part of how L died. She was amazed hearing how Light took his place as the "new L" and how L's true successors, Mello and Near took the initiative to take him down and finish what the true L started. Nona was captivated by the entire tale all the way up to it's end hearing how Light failed during the stand-off between his task force and Near's SPK force, of which Ryuk ultimately killed off Light himself.
Upon hearing this final part of the tale how Ryuk killed Light, left Nona stunned and blown away. The Shinigami had suddenly become more than just a famous figure to Nona, he was magnificent, ingenius.
Nona: That is the most incredible story I have ever heard.
Ryuk: Why thank you!
Nona: Shinigami Ryuk I have an offer I think I want to make you, which will remedy your boring life to an end for all eternity!
Ryuk: Eh?
Nona: I want you to come with me to the Arbiter realm and study the Arbiter I have experimented with!
Ryuk: No kidding?! That sounds fascinating! What exactly have you done to this Arbiter though?
Nona: All Arbiters are forbidden to have any human emotion, but this one, I have inserted emotions into him, and have kept a close eye on him to see how he judges people.
Ryuk: That is certainly interesting hahahahaha!
Nona: I think it would be worthwhile for you to come with me Ryuk and participate in this experiment, I believe you've earned it after the amazing experiment you have accomplished with a human yourself.
Ryuk: My time with Light looks like it is paying off so much more than I ever could have considered! Say what fate was decided for Light anyway?
Nona: We're not to suppose to share that but since you are exceptional, I can tell you he ended up in the void.
Ryuk: Hahahaha. I did tell Light from the start using the Death Note will neither put him in Heaven or Hell!
Nona and Ryuk leave the Shinigami realm and enter the Arbiter realm together.