What's Kyocera to do with an anime adaptation of Koyomi's life?
Adding some more context into this dialog between Oshino and Araragi will make the intent clear:

&quot;Why would our everyday lives get turned into an anime?!&quot;
&quot;Because a drama CD can't convey that wonderful face you make when you act the straight man.&quot;
&quot;It'll be fun, though. It'll be like the ending of Demon-Lord Hero Legend Wataru.&quot;
&quot;I don't think I was even born when that was on the air!&quot;
&quot;You say that, but I see your Kyocera phone. The prospect is so on your mind.&quot;

(This is from Chapter 09, p.142 on the English translation published by Vertical).
Koyomi claims to be young enough not to know about a show from the late 80s, but Oshino makes the point that he's using an old man's phone (probably refers to a flip-phone, compared to the more modern smartphones; remember how Kaiki suffered when Senjougahara broke his phone).
An interesting point is that Koyomi is probably telling the truth: several sources point to the timeline of the show occurring around 2006-2007, and he would not have been born by 1989 when Demon-Lord Hero Legend Wataru finished airing.