Chara was napping on a flower bed on the island. When she opened her eyes, She saw Luffy in front of her.

"Howdy! I actually wanted to talk with you!" Said Chara gesturing Luffy to sit down

"Shishishi! Sure!" Said Luffy sitting down next to Chara

"You seem to have quite an interesting crew." Said Chara

"Hahaha! Aren't they cool!" Said Luffy

"I am starting to see why Frisk would like these new friends and follow you guys."

"You're also part of the crew now too!"

Chara frowned a little.

"What's wrong?"

Chara was silent for a minute. Luffy patiently waited.

"...About that. I'll cut to the chase. Why did you accept me as a part of your crew?"

"Huh?"

"Why didn't you just tie me up or have someone watch me 24/7? Even though I'm taking care of Frisk's body right now, I might just backstab all of you guys, you know?"

"You won't," Replied Luffy simply.

Chara narrowed her eyes, unsatisfied with the answer.

"How do you know that? It's human nature to backstab each other."

"I know you won't."

"That's stupid! If I suddenly attacked you here, that would mean you're wrong!" Said Chara

"But you won't."

Chara stood up from the flower bed, pulled out her knife, pointing it directly towards Luffy's neck.

"You've given me the perfect position, you idiot! I was just pretending all along. I'm going to stab your throat now, and you're going to die. Good bye~" Said Chara emitting the most considerable killing intent she has radiated so far.

Luffy didn't even flinch. He looked directly at Chara with a neutral face, not even shifting a little. Chara moved the knife closer, basically touching Luffy's neck at this point. Despite that, Luffy didn't budge. Chara, losing her cool, made a scrunched up face.

"Hahaha~ You win. You're right. I wouldn't do that." said Chara throwing the knife down away at the floor

"See? I knew you wouldn't," Said Luffy with a grin.

"Man, I've never known I would see another idiot like Frisk. How can you believe in others when there's always a chance they would backstab you?" Said Chara

"I would rather die than not believe in my friends."

Chara's face morphed into confusion.

"You… You even have the same ideals as her. We just met, you know?"

"We did." Admitted Luffy

"Then why? Why do you believe in me?" Said Chara

"Because you're my comrade now."

"...! Hahaha…"

Chara sat back on the floor.

"You're just like Frisk and Asriel… You would rather believe and die rather than doubt… That's impossible for me…"

"That's stupid."

"What?"

"You don't need to believe in everyone stupid!"

"Then who do I believe in?"

"You just need to believe in your friends!"

"I only had Frisk and Asriel as my only friends…"

"I'm your friend!"

Chara made a disbelieving look.

"Like I said, we just met you, doofus."

"Let's make a bet!"

"Are you even listening to me?" Said Chara with a sweatdrop

Chara looked up at Luffy, and he showed the wildest smile.

"Fine... What will the bet be about?" Asked Chara

"I bet that you will come to believe in us."

"If you lose?" Asked Chara

"That means that I was wrong, and I'll quit my dreams as king of the pirates." Said Luffy with a shrug

"That is quite the bargain you're holding there. And if you win?" Said Chara with her eyebrows raised

"That means that I will have one more official member, shishishi!" Said Luffy

"... You know what? Why not. Prove me wrong." Said Chara with a small smile.