Hi guys, I decided to make a fanfic about ukitake's sister, ukitake yasui, who joined his squad as a fifth seat. Enjoy!

Disclaimer: I only own Ukitake Yasui

Chapter 1: Nii-sama

Ukitake Jushiro was the eldest son and he had many siblings. His youngest sister became a shinigami and joined his squad as a 5th seat.

"Ukitake-dono, welcome to 13th squad. I'm kuchiki rukia, fukutaicho."

"Hi, rukia-chan!" Yasui chirped and waved to rukia.

"Yasui! Be more polite!" Scolded jushiro, her brother. Yasui pouted and stuck out her tongue at jushiro.

"It's fine, captain. She can call me rukia."

"Nii-sama, you're horrible!"pouted Yasui. She was as old as rukia. She is a resilient, positive and yet kind girl. Jushiro doted on her the most among all his siblings as she is the youngest. She behaves around everyone, except jushiro. As he was patient, she did not learn her lesson of bullying her brother until kyoraku scolded her the other day they met.

"Kuchiki, would you mind showing her around?"

"No, captain, not at all. Let's go, ukitake-dono."

"Wakata!"

-afterwards-

"Are you more familiar with the places now, Yasui?"asked rukia.

"Yes, rukia-chan. Arigatogozaimasu!"

"Taicho is resting at his estate, would you like to go there?"

"Thank you, rukia-chan. I would preferably go there myself" Yasui said, using shunpo to leave.

-at the estate-

"Nii-samaaaaaaa!" Yasui sang. She felt a little disappointed when she saw ukitake sleeping. Suddenly, she noticed her brother's zanpakuto beside him. She thought of an idea. She crept quietly to jushiro and took his sword.

"Be good, akitori(Autumn bird). I'll get you back later." She whispered as she replaced her sword with jushiro's. Yasui ran out of the estate happily.

-later-

"What a nice nap! Now time for my sword training!" Jushiro yawned and picked up his zanpakuto. "W-what...?" Immediately, he realized the zanpakuto was not his. He ran out of the room and to the practice field, just to see Yasui there, playing with it.

"Yasui!"

"N-nii-sama..."

"Now hand me back my zanpakuto, come on" said jushiro, smiling.

"Ya desuuuuuuu... Baka!" Yasui laughed and stuck her tongue at her brother.

"Yasui, if you give me back my zanpakuto, I will treat you to some... Hey!" Yasui ran off before Jushiro finished his speech. "Nii-sama! Kono Baka!" Yasui jeered and jushiro and used shunpo to dashed off.

-later-

Jushiro had been chasing Yasui for about an hour now. He was running out of breath but now his sister. They were running on roofs to roofs of seireitei.

"Yasui! We've been running for about an hour! I'm about to get angry! I'm warning you!" Jushiro shouted and Yasui.

"As if you will! Stop lying! Lying is bad!" Yasui laughed again and jumped down the roof.

"Yasui! You can't go down there! That's-"

"Chase me if you can, nii-sama!" Yasui ran into the 6th barracks.

"How am I going to explain this to Byakuya now..." Jushiro mumbled.

Meanwhile, Yasui was happily running about in the 6th barracks. She doesn't care about the weird looks the people there is giving her. Suddenly, she bumped into someone. She looked up and saw a tall man.

"Why are you running here?" Asked the man.

"Who are you?" Asked Yasui.

"I am the taicho of 6th division, Kuchiki Byakuya."

"Hi Byakuya-kun! Nice to meet you!" Chirped Yasui, earning a cold stare from Byakuya.

"And who might you be?"

"5th seat of 13th division."

"Why are you here?"

"My brother is chasing me."

"What is your brother's name?"

"Ukitake Jushiro." Byakuya's eyes widened. He picked Yasui up by the shirt collar.

"You are going back to your division."

"N-nani? Hanase! Konoyaro! Hanase!" Yasui struggled as Byakuya used shunpo to go to the 13th division with her in his grip

-later-

"Itai! Itai! Itai!" Yasui shouted upon the swats jushiro was giving her.

"Yasui! I told you I was going to get angry!"

"N-Nii-sama! I'm sorry! I'm really sorry!"

"No Yasui. I will make sure you learnt your lesson today." Said jushiro firmly, bringing his palm down.

"Itai!" Yasui Shrieked in pain.

SMACK! SMACK! SMACK! SMACK! SMACK!

The usually kind and gentle jushiro was really angry now. He kept a firm look on his face and was not going to give in.

"Nii-sama! I have learnt my lesson! I'm sorry for what I did today! I'm so sorry!" Yasui screamed at the unbearable pain on her bottom. She had tears rolling down her cheeks.

"Tell me why I should stop spanking you?" Asked jushiro firmly.

"I should not call you names and running away from you."

"And?"

"That's all." SMACK! Her answer earned her a firm spank from her brother.

"How about stealing my zanpakuto?"

"That was just for fun! That wasn't wrong!" Yasui protested.

SMACK! SMACK! SMACK! SMACK! SMACK! SMACK!

No matter how hard Yasui cried, Jushiro kept spanking her. Yasui couldn't stand the unbearable pain any longer she finally admitted that stealing was wrong.

"Will this ever happen again, Ukitake Yasui?" Asked jushiro as he folded his arms.

"No, nii-sama..."said Yasui, sobbing.

"Ok, good. Here..." Jushiro picked up Yasui and hugged her while letting her cry in his arms. He rubbed her back to comfort her.

"Yasui... Byakuya said you have been disrespectful to him. Is this true?"

"No..."

"Would you like another spanking?" Jushiro asked threateningly.

"I did not, nii-sama... Please don't spank me anymore! I just said hi to byakuya-kun, that's all!" Yasui hugged jushiro more tightly.

"Oh I see." Jushiro chuckled. "Yasui, you should know that you should address him as taicho, that's respectful. And also address other taicho and fukutaicho as such also, do you understand?"

"Yes, nii-sama..." Yasui's voice trailed off. Jushiro laid her down on his bed and pulled up the covers till her neck. He rubbed her long white hair and said softly, "I'm sorry Yasui... I'm so sorry."

Yasui was the youngest child in the family. Their mother caught tuberculosis from Jushiro when he was young and she was pregnant with Yasui. When she gave birth to Yasui, she died and passed tuberculosis to Yasui. That caused her to suffer during her whole childhood and turned her hair white. Her condition was much more worse than jushiro as she sometimes might throw up, faint, or vomit blood and it will take a longer time than jushiro to recover.

Upon seeing his sister sleeping so soundly, jushiro ruffled her hair and smiled. "I'm glad you forgave me."