Assassin princess x reader

The mission

Y/N's POV:
After the few days off with Miku and Rin, I have been feeling a lot better since that last mission. I heard we got a bit more information on those people keeping that strange girl hostage. All was going well until Luka had called us into her office for a mission. " So, I have a mission for you three, with the info we have got about those people, we found out where their main base is. Now Rin, your brother went out on a mission 2 days ago and hasn't come back, we are assuming they caught him and might be doing what they are doing to that girl Y/N encountered, therefore you three will go to the designated location and report his condition, and bring him back if he's alive." Luka told us, Rin looked horrified, I didn't know she had a brother... I did catch Miku wear a slight worried expression until she went back to her cold and emotionless one. "Yes ma'am, we will not fail this mission." Miku says to Luka, I guess we have no choice but to take this mission, maybe I can see that girl again... "Rin, are you gonna be okay?" Miku looks at Rin, Rin's head still down, Rin replied "I'm fine. Lets go." I can tell she's not okay, but I can't get distracted from my mission.
Time rewind, ????'s POV:
I've been here forever, I don't understand why I'm supposed to guard this place, it's not like anybody is going to try to break in- wait- I swear I heard footsteps. Is somebody seriously stupid enough to break into here? I have no choice but to find and eliminate them though, what a pity. I keep walking and hear the footsteps getting closer and closer, are they coming to me?! Do they have a death wish or something?! "Who's there!?" I yell out, I see a bit of yellow in the corner of my eye. I walk toward the spot and hear quiet breathing. I pull away the boxes and sheets and find a small, yellow haired boy, quivering while looking at me in fear. I look at him and reach out until I see a slight glimmer come from somewhere, i move his arm and find a necklace. "Wait a minute. Where did you get that?" I say, now with a surprised look in my face. "I-I'll tell you everything just p-please, don't hurt me..."
Y/N's  POV:
Once we got to the location, we all felt a feeling of dread come over us. "All right, we will split up and try to find something." Miku says to me and Rin, all three of us go in and turn different ways. I wonder what could be in this place...
Time skip
I've been walking for awhile but I've found nothing, though I have been feeling somebody watching me, which means I'm not ready able to go meet with the others just yet, I have to get rid of whoever is following me.
Another time skip
Again, been walking for about 10 minutes but still nothing, and whoever is following me is still not gone. "Alright whoever is there, come out." I coldly speak, and pull out my knives ready to fight, but nobody comes out. "I'm warning you! If you come out now, I may spare you. If I have to find you, it's going to be-" I can't finish my sentence before a shrill high-pitched scream echoes through the halls, I recognize the scream immediately, it was Rin. I start running toward the sound, but a girl steps out- no, it's the girl from that one mission! She had her hair into two drills on the side of her head and was wearing a bunch of buckles over her eyes, I feel like I've seen that hairstyle before... no time for that I gotta get through! "What do you want? Why were you following me?" I yell at her, she doesn't get into battle stance nor does she reply, she just walked toward me, something told me she had good intention, it was dumb but, I felt like I was frozen at that time. "Come on, I know where your friend is." She says quietly, she then started running the other way and I let her lead me.
Time skip
"They're here. I caught the blonde boy but kept him safe in here, you should take him and then-" She stopped in her tracks when we both heard Rin's crying, I bursted through the door despite the girl telling me not to. I saw a sight that I wish I could unsee, Len's dead body being held close by Rin. "R-Rin, what happened?! I thought you said you kept him safe!?" I kneel down to Rin and put my hand on her back, and turn to the girl angrily. "I-I, I don't know how this happened... I didn't want this to happen, I never even touched him, I swear-" The girl goes on until a shriek sound of metal sounds out through the building, there stands that one brunette woman, holding a metal pipe, and staring down at us with Miku in her other hand. "Take that girl, we'll make a trade for this green one." She says to us and picks the girl up and throws her at us, I try to get up but before I knew it, the brunette was gone. I tap on Rin's shoulder, and tell her that we need to leave. I call Luka while Rin picks up Len. I hang up and lift up the red-haired girl. We then leave after getting a ride sent from Luka. She really won't be happy about this one... at least we got this girl to give us information.
Meiko's POV:
"You idiot! You realize how valuable she was?! You can't just give her away after we had just gotten some valuable information from her for once, besides she was doing great at defending us and taking out whoever crossed our path!!!"
Boss yells at me furiously, I reply slowly and as calmly as possible. "Sir, you have to understand that we have this one now, she's even better than that Teto girl! Now all we have to do is wait for them to attack since they will want her back, and seems the blonde girl wants to avenge that one guy's death by taking us down." My boss looks at me, he closes his eyes furiously and sighs. "Fine, but do not do something like this again!" He says to me. "Yes sir, I'll be leaving now." I say and exit his office, seems like in the end my plan worked, I finally don't have to deal with that brat anymore.