A/N: like I said this is a soulmate AU and a modern day AU all in one. And you are Yamato's little sister in this one but just by one year.
Sixteenth birthdays are big yes, but this time 16th birthdays are big but for a different reason. You see people get a name written on a random part of their body and whose ever name is on your body is your soulmate, now not everyone gets a soulmate. There are some that don't have a name on their body they get called the loveless.
Y/n's POV
"Y/N WAKE UP!" I heard my father Kaido yell from downstairs. "I'M UP!" I yelled back I got out of bed and went to the bathroom I looked at my arm to see if I got a name I sighed. "Looks like I don't have one." I mumbled. Then as I was brushing my teeth I saw black ink starting to form on my wrist, once I got down brushing my teeth I looked at my wrist. 'Portgas D. Ace' was written on my wrist. I was shocked Ace was Yamato's boyfriend who happened to also be my older sister. 'Did Ace show Yamato this?!' Do I have to show her this!?' Then a knock on the bathroom door brought me back to reality. "Y/n are you almost done?" I heard Yamato voice asked me. "Y-Yeah!" I told her. "Great, oh and happy birthday." She told me. "T-Thanks." I told her. I heard her footsteps walking away, "Phew." I said, I walked to my room to get dressed. "I should probably cover this up." I said as I was looking at my wrist, I grabbed a f/c hoodie and put it on. Then I went downstairs to eat breakfast. "Good morning everyone." I told Yamato and my father. "Again Happy birthday! Did you get a soulmate?" Yamato asked me. "Oh uh no I didn't." I lied. "You too?" Yamato said. "Y-Yeah." I told her, Yamato didn't get a name on her sixteenth birthday, even though she still decided to date Ace. I ate my breakfast, "I thought you were going to get one." Yamato told me. "Well yeah I guesss not, plus I'm fine with it." I told her, then I heard a honk from outside I looked and saw Nami. Right she was gonna give me a ride... I grabbed my stuff "see you at school Yamato!" I told her as I ran out the door and got into Nami's car. "Happy birthday Y/n!" Nami told me. "Thanks." I told her. "So did you get a soulmate?" She asked me. "Yeah I did, but it's bad." I told her. "What do you mean?" She asked me as she was driving out of the driveway. "Its Ace." I told her. "HOLD UP ACE AS IN YOUR OLDER SISTERS BOYFRIEND ACE?!" Nami asked me. "DUH!" I told her. "Did you tell Yamato yet?" Nami asked me as she pulled into the school parking lot. "What do you think?" I said as we got out of the car. "So are you going to tell her?" Nami asked me. "I don't know." I told her as we was walking to the entrance of the school. "Maybe Ace already told her." Nami told me. "If Ace told her then they wouldn't still be dating." I told her. "Y/N! NAMI!" I heard our names being called out and we looked and saw Luffy, Zoro, Sanji, and Vivi and Franky. Luffy was running over to us he was pulling Zoro with him and the rest was following behind them. "Hey guys." I greeted him. "Happy birthday Y/n!" Luffy said. "Happy birthday my lovely Y/n-swan." Sanji told me. "Happy super birthday!!" Franky also told me. "Oh yeah happy birthday." Zoro said. "Happy birthday Y/n!" Vivi told me. "Thanks guys." I told them. "So did you get a soulmate?!" Vivi asked me. "Oh right! It's your sixteenth birthday today isn't it?" Franky said. "Yeah." I said. "Is your soulmate me?!" Sanji asked me. "S-sorry no, it's someone else." I told Sanji. "Did you really think it would actually be your name?" Zoro said. "What was that mosshead?!" Sanji said then those two got into a fight. "But seriously who is your soulmate?" Vivi asked me. "Well uh you see..." I started to say, "I didn't get one." I told her. "Liar, when Sanji asked if it was him you said no it was someone else." Vivi told me. "I don't wanna say." I told her. "Is it somebody bad?" Vivi asked me. "No, he's a good person it's just one of those situations where it's good but it's bad." I told her. Vivi looked confused and then looked at Nami. "Yeah it is." Nami told Vivi. "I know who Y/n's soulmate is." Luffy said. "You do?!" Vivi said. "Is it you Luffy?" Sanji asked him. "No it's not me, it's-" before Luffy could finish the bell rang. "Saved by the bell." I said. We all went separate ways because we have different classes, my first class is Literature with Shanks, which also is Ace's first class. I walked to class when I got in I saw Ace sitting in his seat and talking to Usopp. I walked over to my seat which was unfortunately in front of Ace. "Happy birthday Y/n." I heard Ace tell me. "T-Thanks." I told him. "Let me guess you didn't tell Yamato did you?" Ace said. "Y-Yeah I didn't." I told him, "Did you?" "I was going to but-" before he could finish Shanks walked in. "let's talk more after class okay?" Ace said. "Okay." I said.
Ace's POV
I was talking to Usopp about some stuff. "Oh yeah Y/n's birthday is today." Usopp said. "Oh right." I said, "Today is the day she will find out who her soulmate is..." Y/n walked in and I went back and acted like I was talking to Usopp. "So you gonna say happy birthday to her?" I asked Usopp. "Of course! She's my friend." Usopp told me, then I saw her walking to her desk and sat in front of me. "Happy birthday Y/n." I told her. I saw her stiffen up. ' She knows, well of course she knows! It's her birthday!' "T-Thanks." She told me. "Let me guess you didn't tell Yamato did you?" I asked her. "Y-Yeah I didn't." She told me, "Did you?" She asked. "I was going to but-" before I could finish Shanks walked it, "Let's talk after class okay?" I told her "okay." She answered back.
After class Y/n's POV
Once class was down Ace pulled me to the side. I rubbed my wrist "I can't believe you are my soulmate..." I told him looking down. "Same." Ace said. "How are we going to tell Yamato?" I said, "I told her that I didn't have one because I didn't want to hurt your relationship with her." I told him, I started to cry a little which made Ace hugged me.
Third Person POV
Little did Ace and Y/n know that Yamato was listening to the whole thing. "Heh, I knew it..." Yamato said with a sad smile. Then when Yamato walked in front of Y/n and Ace. "Yamato we can explain!" Y/n told her. "Don't worry I know." Yamato told them. "You did?" Ace asked her. "Yeah, I saw your arm by accident and I saw my sister's name written across it." Yamato told Ace, "Don't worry I'm not mad or anything..." Yamato said, then she looked at Y/n. "I'm just glad that you found a soulmate." Yamato told her, "Same with you Ace."
"So I guess this means we're uh over?"
"Yeah."
"It was nice Ace, it really was."
"Same."
Yamato just walked away, Y/n and Ace felt guilty especially Y/n, she looked down at the ground Ace knew how she felt. So he lifted up her chin and gave her a small kiss on the lips. "Yamato would want us to be happy." Ace told her. "Right." Y/n said. Then Ace kissed her again. "HEY NO PDA IN THE HALL!" They heard Akainu who is unfortunately the vice principal of this school.
Y/n's POV
Ace rolled his eyes, "It's okay Ace, we can do more after school." I told him. "what is that supposed to mean?" Ace asked me. I jabbed him in the guts "I mean we can go on a date you pervert." I told him. "Yeah sure you did." Ace said. "I will jabbed you in the gut again." I threatened him. "Okay okay." Ace said.
The end should I do a part two with them going on the date? Sorry if this was bad and if anyone was OOC comment vote and follow I take requests otherwise peace out ✌🏻
