Author's Note: I came up with this off of the top of my head after watching an episode of Grim Adventures of Billy and Mandy. It's in my opinion of why Kaiba never smiles, and it's supposed to be really goofy, and it based of that one episode of Grim Adventures. So, laugh and enjoy this one shot:

Why Kaiba never smiles:

Yugi ran into his archrival Seto Kaiba on day. Kaiba was again in a bad mood, and didn't appreciate the fact the fact that Yugi wasn't looking where he was going and walked into him. Kaiba spoke:

"It's you again! Why are you always in my way? Especially when I'm in a bad mood?"

Yugi said, "Why don't you try smiling Kaiba? It would make you feel better?"

Mokuba, who was also with him, asked:

"Yeah Big Brother, why don't you ever smile anymore."

"Mokuba, there are some things in this world that is not meant for the human eyes to see…"

Atem, who was in the puzzle, traded places with Yugi and challenged Kaiba by saying:

"Why Kaiba, are you scared to smile?"

Atem let out a laugh and Kaiba stated:

"You are the worst of the two. Yeah, they only worship you because you just happen to be a pharaoh. Not that I believe it though, to me, that's all a bunch of crap…"

Atem said, "You know what I think Kaiba? I think you've forgotten how to smile!"

Mokuba agreed, "You can say that again Atem…"

"Go on Kaiba…I DARE you to smile!"

"I can't smile you idiot! You don't realize what would happen if I smiled! It's horrible…that's why I have vowed never to smile again."

"I triple dog dare you to smile. I learned that phrase from my good friend Yugi."

"You didn't just triple dog dare me! You know I can't back down from a dare…"

Mokuba stated, "Oh no…here we go again. Let me get out of here before something crazy happens. Again…"

Seto said, "Yes little brother, you better leave now so you don't have to suffer the hidden horrors of my smile."

Mokuba ran away. Kaiba let out a laugh and exclaimed:

"You don't know how long I have waited to get you back Atem, and this time…this time I will do it! By smiling!"

Kaiba let out another laugh. He then tried to flex his unused muscles to smile. Yugi appeared next to Atem and asked:

"Whoa…look at that! Those muscles are so unused that he has a hard time moving them!"

Atem agreed, "Yes, I know. But I want to see for myself what his smile can do!"

"Are you sure this is a good idea?"

"We won't know until it's done I'm afraid…"

Kaiba then finally managed to move his muscles into a smile position. Yugi and Atem gasped at this. A bright light then projected from Kaiba's smile. Yugi then yelled out:

"Atem! What have you done?"

"I didn't do anything! But it looks like the whole fabric of reality is falling apart!"

"I'm scared…"

"I would hold you, but I'm a guy and that would look so wrong. Plus, I'm in love with Anzu…"

The three of them melted into the fabrics of reality. Seconds later, an alarm woke them up and the professor from the Powerpuff Girls barged in an exclaimed:

"Girls! Girls! Wake up! It's time to save the world!"

They threw off the covers, and screamed when they found themselves in dresses. They flew out of the building. They even looked like the Powerpuff girls. Atem looked like Blossom, Yugi Bubbles, and Kaiba Buttercup. Kaiba snarled and exclaimed:

"Now you see why I never smile! It always leads me into this twisted reality where my head and eyes are freakishly large and I have no nose!"

Atem spoke, "Ugh…you got me Kaiba. I wouldn't smile either if I were doomed to this reality…"

Yugi randomly said, "I miss my nose!"

Kaiba spoke, "Let's just fly away from this and never speak of it again…"

The end!

Author's note: This was based off of the episode of Grim Adventures where Mandy enters a beauty pageant and has to smile to win. But when she does, she throws Grim and Billy into the Powerpuff reality. Since Kaiba almost never smiles, he seemed perfect to act out that part. But I needed three people, so I put Yugi and Atem in two! I hoped you enjoyed this crazy one-shot of mine! See yah!