The day my life turned for the worse.......or for the better?

Shift 1

"Uhhhhh. What a waste of precious living time", I groaned as I arrived at my house and putting my stuff onto a hook.

     "I'm back from......school?" I asked at the end cause the house was eerily quiet. Like it was an abandoned asylum quiet. I decided to flop on the couch with a 'FLOOMPH' and watch TV. Unbeknownst to me, someone is walking, more like tiptoeing, behind the couch and I was completely oblivious to the small creaking noises. But then again, I was watching TV.

"BBBIIIGGGGG BBBBBRRRROOOOO!!!" A loud ear-piercing shriek was heard, and it was loud enough to drown out the TV.

  "AAAAAACCKKKK-OOMPH! Geez, Saya! That hurt and get off my back please." All of that dialogue was my reaction to a bundle of joy mixed with frosted ice-cream cupcakes and 5 tubs of ice-cream. What I just described is the hyperactivity levels of Saya Sakamoto. My younger sister. She's 14 while I'm 15. Yup, I have a younger sister. Though I prefer to be alone, I am much more paranoid when I am alone and I pretty much require at least some form of human contact.
   Though, back to Saya. As I said she is my younger sister, though we aren't blood-related, both of us are adopted by three other people who live in the same house as where I am. And as for the reason why Saya didn't arrive with me after school was because she goes to an all-girls school and her school ended 2 months ago, whereas mine has 34 days left till end.

  "Aniki is back!" She squeals in joy as she hops on, more like destroys my spine and, my back.

"Get off of me!" I freaked because of the pressure she is applying to my poor back and spine.
Numerous thoughts popped into my head on how to get out of this situation. But I decided on tickling her. What harm could come to it. I will eventually regret this in a couple of minutes. I twist a little to the right and stuck an arm out to reach Saya's side and tickled her.

She giggled and squealed like a little school girl before falling on her side. I took advantage of this and rolled to my stomach and pounced Saya and began tickling the hell out of her. She retaliated and we have a full tickling war on play. That is until I accidentally groped her boobs without noticing and she let out a moan. A pleasure induced moan at that to boot.
'What the fuck was up with that moan?' I mentally questioned myself and then realizing that I am squeezing something soft in my hands. Then I did a quick take and look at where my hands were and almost fainted on the spot and probably died. I intended to release my hands but due to my state of panic, my grip on her breasts increased and she let out a louder moan. Thank God that there was no one but us in the house. I did another quick take and instantly removed my hands from her while blushing scarlet profusely and started shuffling away from her. Saya realised why she was moaning, shuffled to the opposite direction, though slightly and also blushing profusely.
An awkward silence fell on the both of us. We then looked at each other. I decided to break the silence.
"Hey. Uhh, sis?" I said as I look at Saya's eyes, still red in the face.
"Yes, aniki?" She asked as she also looks at me in the yes with her embarrassed face.
"I'm sorry." I muttered quietly as I look away from her.
"Did you say something?" She asked concerningly and shuffled a little closer despite our incident a couple of minutes ago.
"Nothing" I denied as I raise my hands and wave them around while shaking my head side to side.
"Oh come on. I know you said something." She looks at me with a pouty face. Then she smirked and gained a small blush on her cheeks,"Or I will kiss you on the lips."
I instantly shot up and looked at her in disbelief.
"Wait what?!"
"You heard me right."
"You won't do it right?"
"I will. And I will make sure it's on the lips."
"You wouldn't dare."
"Oh yes I will."
"Fine. You win. All I said was sorry and that was because I groped you." I made a melancholic sigh as I finished my sentence.
"Oh...........oh. Okay. Apology accepted." She answered meekly. Another awkward silence befalls upon the two of us. Said silence was then broken by the door slamming against the wall.
"Aleks! Saya! We're home!" A female voice bellowed.
"Ohayo gozaimashtaa." Another female said though this one was tolerable.
"LLLLLLLIIIIIIITTTTTLLLLLLEEEEEEE BBBBBBRRRRRROOOOOOOTTTTHHHHEEEERRRR!" Another female practically screamed out. Then the three notice Saya and I sitting on the couch silently.
"Okay. What happened here?" One of them asked.
"Uuuhhhhhh........" I trailed off. "Just a small incident. Nothing to worry about."
I waved my hand lazily and made a small casual shrug. I sighed and thought, 'This is going to be a long night.'