Cat Returns is the 4th Track on Saiyuki's Drama CD, Saiyuki Party.
Sanzo heard a cat's meow in Goku's stomach as he suspected something. There was a kitty that Goku was hiding as it was revealed what Sanzo's weakness, yes, he's allergic to cats. The story is a little bit similar in the 7th Episode of Saiyuki Reload, Little Partner.
[Sanzo]: Those guys are sure late. Where the hell did they go to get groceries?
[Goku]: Uhm, yeah!
[Goku's stomach]: Nyan~~ nyan~~
[Sanzo]: Oi, little monkey.
[Sanzo]: Just right now, coming from your stomach. I heard a voice crying "Nya nya".
[Goku]: Uh--- that was me! It was me! I said it! Just watch! "Nya nya!"
[Sanzo]: Oh? And why would you do that?
[Goku]: C-cat cough?
[Sanzo]: If that's your excuse then take off your clothes!
Sanzo takes off Goku's clothes
[Goku]: W-w-wait a second! St-st-stop! Wait! Nya nya nya!!!
[Hakkai]: We're back- (Hakkai & Gojyo misunderstood what they see Sanzo doing to Goku.) Please excuse us.
[Sanzo]: Hey! What are you doing?
[Gojyo]: Man, just what exactly have we interrupted, you tw- (Gojyo said but was cut of when Sanzo slaps him with the paper fan) That hurts! When the hell will you learn to take a joke?
[Sanzo]: It is not worth telling if it's someone like you.
[Hakkai]: Well then, what exactly is going on here?
[Gojyo]: What? A kitten?
[Hakkai]: Why do you have that, Goku?
[Goku]: A little while ago, I found it out on the road.
[Sanzo]: And that's where it's going back too.
[Goku]: No way!
[Sanzo]: No way, is it?
[Goku]: No way! Because he was out in the rain crying "nya nya"! So I decided to take it with me!
[Gojyo]: Sneaking him in like that just makes you seem like you already want to be his owner.
[Goku]: Sanzo, at least let him stay until the rain stop. I mean, come on! Look how tiny and adorable it--
[Sanzo]: DON'T BRING IT NEAR ME!
[Hakkai]: Sanzo? Uhhh!
[Gojyo]: Don't tell me... you're afraid of cats--
[Sanzo]: Wh-wha-what the hell of story are you spinning? (Hyperventilating)
[Hakkai]: He says that but he is given up his space hasn't he?
[Goku]: Is Sanzo... the type of person who run away from cats?
Sanzo is panting and trying to breathe.
[Gojyo]: He's scared isn't he?
[Hakkai]: He is, definitely!
[Goku]: Eh?! Of something tiny?
[Sanzo]: Keh! Who would be scared something like---
[Goku]: Here you are! (Goku places the kitten near Sanzo)
[Sanzo]: (Sanzo Yells, then) I told you to keep it the hell away from me!
[Goku]: (Laughing) Sanzo's hilarious!
[Sanzo]: Stop messing around you shitty monkey!
[Goku]: C'mon! C'mon! Look at it!
[Hakkai]: Goku's become quite a little sadist, hasn't he?
[Gojyo]: He can be amazingly cruel sometimes, huh?
[Hakkai]: Oh, that's right. Mr. Cat probably hasn't eaten yet. Shall we see if there's something for him to eat in our groceries?
[Goku]: Yeah! Whacha got?
[Hakka]: Let see... hi-lites, beer, cola, myoga, kinugoshi tofu and...
[Gojyo]: None of that sounds good.
[Hakkai]: Ah, we have (Snack food)! This should do nicely shouldn't it?
[Goku]: Thank you! Here you go. Eat it! (Goku gives the kitten a snack)
[Kitten]: Nyan~ (Eating)
[Goku]: Wow! He's eating, he's eating!
[Hakkai]: And quickly too! It must have been very hungry, wasn't it?
[Gojyo]: Goku? Why are you drooling like that?
[Goku]: Just watching it eat... is making me hungry as well.
[Hakkai]: Yes, yes. Then shall I make dinner for all of us? And... what are we going to do about that kitten?
[Sanzo]: It's satisfied already since it's been fed. Hurry up and toss it out!
[Gojyo]: When Sanzo's acting this funny, it should be okay to let it stay longer.
[Sanzo]: Don't mess around with me, you bastard!
[Hakkai]: This can all wait until later. Shall we have dinner?
[Sanzo]: Hey! When the Hell should it wait till?
[Goku]: Amazing Hakkai! Dinner's already ready?
[Hakkai]: Well, yes! Because it's only yudofu and hiyayakko.
[Goku]: Eh?! That's it?!
[Gojyo]: It can't be much else considering we've only got tofu.
[Sanzo]: We've got one Hell of a shining-white dinner table tonight, huh?
[Hakkai]: Consider the time that you sent us out to buy food? There weren't any grocery stores open this late. We didn't buy anything other than tofu, myoga and the snack.
[Sanzo]: In the case... the snack food and something mixed with it is fine.
[Goku]: Ah! This little guy has eaten all of it!
[Sanzo]: Throw it out into the tsunami right now!
[Goku]: Ah-wa-wait a minute! L-look, Sanzo! This little guy says "Forgive me-Nya!" right now!
[Gojyo]: What does nya supposed to mean?
[Hakkai]: Gojyo, Gojyo. You're being strung along.
[Goku]: Shut up-nya, kappa!
[Goku]: Nyan the Hell?!
[Sanzo]: YOU BASTARDS GOING NYA NYA IS ABSOLUTELY ANNOYING!
[Gojyo and Goku]: NYAAAAA!!!
[Sanzo]: What, Hakkai?
[Hakkai]: During all of this commotion it seems someone has left, doesn't it? The kitten?
[Goku]: Eh?!! (Looking for the kitten) It's true...! He disappeared!
[Hakkai]: Staying here with all of us might have just been a little too much for it to take after all.
[Goku]: (Sad) I see, it headed back out.
[Gojyo]: Well, that's it! That kitten may eventually return some day, you know?
[Gojyo]: Yeah! It may just return to sneak pervertedly under the covers of some beautiful young woman's bed.
[Hakkai]: That kind of story will always apply much more to Gojyo, won't it?
[Goku]: That little guy... I wonder if he'll really be alright in this rain.
[Hakkai]: I'm sure it's fine!
[Sanzo]: Hey! Dinner remember? Let's hurry up and eat that yudofu and hyayakko. Hell even fried tofu will do.
[Goku]: Ah, that's right! We're obligated to have made tofu if we have everything else.
[Hakkai]: Well then, we can at least eat something together, right?
[Gojyo]: And that's... what choice are we making anyway?
[Sanzo]: Whichever choice is a good one.
[Kitten]: Nyan~ nyan~
[Hakkai]: Sanzo! At your feet! At your feet!
[Kitten]: Nyan~ Nyan~
[Goku]: It's you! You were hiding in Sanzo's robes all this time!
[Sanzo]: (YELLS like his dying)
[Hakaki]: Seems you're the chosen one for him, Sanzo.
[Gojyo]: Don't you feel so lucky, Sanzo-chan?
[Kitten]: Nyan nyan~
[Sanzo]: Don't come near me! Get off of me! Makaaaiii TEN--
[Hakkai]: Don't tell me you plan on using such an attack on one tiny little defenseless kitten?!
[Sanzo]: (Practically hysterical) Shit!!! (Marches down the hall yelling)
[Goku]: Ah! Sanzo ran away!
[Gojyo]: His strongest foe turned out to be a kitten, huh?
[Hakkai]: Kougaiji and his team don't even come close, do they?
[Gojyo and Goku]: That's right-nya?