that's Asakura Ryouko, I think...

Nope. Ryouko does not have such a sexy laugh.

The title also says "Mikuru and Tsuruya."

I'd translate it but I don't get the joke. Mikuru says like "Um and then," and Tsuruya starts laughing.

The joke is that Tsuruya finds Mikuru telling the joke funny, not the joke itself.

Yes, and something that simple isn't served by a translation. It relies on the sight gag of Mikuru excited in the second panel and Tsuruya laughing in the 2nd, 3rd, and 4th.

Reminds me a Peanuts strip.

Rather, it's so subtle I can't think of any way to translate it and have it be funny (Probably because I didn't find it funny)