It was April Fools Day today and Chen is planning something at Varia...

Chen: What prank should I do this year? :)

Hmmmm...I'VE GOT IT! what about a shark in a bathtub!

Chen: Now i just need Squalo's box weapon...how do i do that?

Squalo: VOOOOIII! CHEN! WHAT ARE YOU MUMBLING ABOUT?!

Chen: YOUR CROTCH!

Squalo: Grrrrrrrr...

Chen: NOW GET YOUR STUPID CROTCH OUTTA HERE!

Squalo: Then your cleaning the bathrooms after this...

Chen: Sure, Whatever...

Squalo leaves

Chen: *starts convicting someone guilty of crime while rapping*

Hanzai toshi... Gensoukyou... darakushi kouhai shita seigi wo shin no sugata ni modoseru no wa
Hou no bannin de aru watashi shika inai no da wa!

Kaitei - zaijou wo tsukitsukete
Suitei - kantei no kekka zantei
Zentei - yuuzai tonikaku yuuzai
Shirokuro hakkiri tsuke danzai!

Reimu! Binbou kouhaku miko. Jitsu wa senkakubanrai chuu
Touhou GEEMU wa otoroezu doko ga binbou da kono sagi onna!

Suika! Yoppage RORIITA youjo ONI. Jitsu wa nenchaku SUTOOKAA
Ichi oku nen to ni shuu kan mae kara dokodemo omae wo mitsumeteru!

Sanae! Choushi koiteru seijun kidori no UBU na miko
Jitsu wa zankoku KOJUUTOME

Marisa! Kono nusutto kari PAKU nori PAKU PAKKU PAKU!
Ano ko no kokoro mo PAKKU PAKU

Chiruno! Baka baka baka baka baka baka baka baaka baka!
Jigoku ni iku ni mo ataisezu

FURAN! Sono uu uu iu no wo yamenasai!
Yamenasai! Yamenasai! Yamenai to korosu wa yo! Kii!

Squalo: SHUT THE FUCK UP CHEN!

Chen: STOP SAYING CUSS WORDS!

Squalo: THEN STOP RAPPING!

Chen: FINE!

Xanxus: WHY DON'T YOU BOTH GO SHUT UP!

Chen & Squalo: *silence*

Chen: ...*secretly takes Squalo's box weapon and ring*

Squalo: Huh? Did I just feel something?

Chen: Probably Xanxus's sound waves from his yelling...

Squalo leaves again

OK! I've got the box and the ring but how do I ignite the flame?

Chen: *struggles* *flame ignites* COOL! I DON'T NEED AN EMOTION FOR THIS! :D OPEN BOX!

shark comes out

Chen: Aww you need a bath! *goes to washroom*

~2 hours later~

Squalo enters washroom naked and sees Chen

Squalo: C-C-C-C-C-C-C-C-C-CHEEEEEEEEEEEEEEEEN!

Chen: Yes? YACCHATTA! ("Yacchatta" means "I've done it" in japanese)

Squalo: WHEN DID YOU TAKE MY BOX WEAPON AND MY RING?! PLUS WHY THE HELL IS MY SHARK IN THE BATHTUB AND WHY ARE YOU...

~5 hours later~

Squalo: YOU'VE GOT THAT?!

Chen: I'm sorry I didn't hear you that time, could you repeat that?

Squalo: *chases Chen around Varia*

~ Epilogue ~

Chen and Squalo both got punished my Xanxus-sama, and yes, Chen and Squalo are frienemies. And a tiny part during the washroom incident:

Chen: *brushing Squalo's shark's teeth*

Squalo: VOOOOOOOOIIII! DO YOU HEAR ME CHEN?!

Xanxus: *yells* I HEAR YOU PERFECTLY!

Chen: Squalo...

Squalo: WHAT?!

Chen: SHUT UP!

Squalo: VOOOOOOOOOOOOOOOOIIIIIII! DON'T TELL ME TO SHUT UP!

Chen: AND DON'T TELL ME WHAT TO DO, LESBIAN!

Squalo: I AM NEVER GOING TO GIVE YOU A B-DAY PRESENT AGAIN!

Chen: AND I'M GONNA MAKE YOU AGELESS AND PUT MORE THAN 2,000 CANDLES ON YOUR B-DAY CAKE AND LIGHT IT ON FIRE BY USING A TORCH!

Squalo: ...T^T Your gonna light my cake on fire? WAAAAAAH!

OK, The last part didn't happen...