Author's Note- This is a sequel to Ninja Turtles' story The Newest Superhero. It takes place two days after. It's in the same AU as the previous story with the mix of Yu Yu Hakusho's manga and anime and Yusuke still working for Koenma.

Disclaimer- I don't own anyone but Tyson, Rodney and Adonis.


Yusuke's Little Brother

Chapter 1-Old Friends meet and Sibling Rivalry Begins

Near the Tokyo Airport is Atsuko Urameshi waiting for a person. A few planes come and go but the last plane stops and she sees a person she recognizes. It is a teen with black ruffled hair with a gray hat on his head with white tennis shoes blue jean and sleeveless shirt. It reveals to be Tyson. Atsuko goes to him and hugs him and he hugs her back. She smiles at him. He smiles back.

"Well how's my other son doing lately?" Atsuko asks Tyson rubbing his head.

"Been doing good, mom, dad wanted me here with you since he figures I'll stay out of trouble in New York." Tyson says to Atsuko smiling.

"I know, baby, now I can introduce you to someone you haven't seen in 6 years."

"Who, mom?"

"Your brother."

"What! Mom, you know me and Yusuke don't get along so well."

"You'll be fine! Yusuke got his own apartment."

"Ok, mom, I don't think Yusuke wants me at his apartment."

"Don't be silly, he'll be fine."

Tyson and Atsuko get on a train back to Sarayaski. They get a cab to an apartment that is near where Yusuke's apartment is. The cab rides all the way to where Yusuke lives. Tyson and Atsuko gets out and pay the cab driver. Tyson and Atsuko get to floor Yusuke lives on. Atsuko goes to the door and she knocks on the door. The door opens and it reveals to be Yusuke with his hair down. Yusuke looks at his mom and frowns knowing what she wants. He notices a person behind her.

"Mom, what are you doing here? I don't have any money and who that behind you?" Yusuke asks annoyed looking at his mother. Atsuko smacks Yusuke across his head. "Ow! Mom!"

"Don't be rude, Yusuke, I'm not asking for money." Atsuko says annoyed then turns excited and pushes Tyson forward. "This is your brother, Tyson, remember I know you haven't seen him in six years."

"My half brother! What the hell is he doing here?"

"He is going to stay here in Japan for a little while. Besides you two need to catch up so can he stay here with you?"

"What!" Yusuke says in shock " No, mom, he's not staying."

"Come on, Yusuke, he won't get into trouble."

"The trouble he causes, mom. Beside I'm not taking care of him for free."

"Bro, I have a job, I'll help pay for my part." Tyson says seriously looking at Yusuke. "I promise I won't get trouble this time, Yusuke."

"Ok, you can stay." Yusuke says seriously looking at Tyson.

"Ok, you two get along now." Atsuko says as she hugs Tyson and Yusuke and she leaves.

"Ok, can I come in, bro." Tyson asks Yusuke seriously as Yusuke stops him.

"I'm giving you a warning, Ty, if you slip up one time, I'm kicking your ass and you're living with mom." Yusuke says seriously looking at Tyson.

Tyson nods in agreement. Tyson walks into Yusuke's apartment and he notices there are no couches and other furniture like he had in America. Yusuke tells him to take off his shoes. Tyson does and puts them near the door. Yusuke and Tyson go into the kitchen and Yusuke makes lunch for both of them. Yusuke gives Tyson his lunch.

"Thanks, bro." Tyson says gratefully eating his lunch.

"Welcome." Yusuke says gratefully but turns serious. "So how's life."

"It's good, like I said I have a job and I like it."

"Really?"

"Yeah, what about you, bro."

"Yeah, I have a job too as a cook."

"A cook, no wonder this taste awesome!"

"Thanks, you wanna see your room?"

"Yeah."

Yusuke shows Tyson to his room. Tyson goes in and he puts his stuff on the floor. Yusuke tells Tyson he has to go to work. Tyson tells him ok. Yusuke gets dressed and walk out as Tyson locks the door. Yusuke walks to his landlord and tells him about Tyson living and paying for his half of the apartment, which the landlord agrees to. Meanwhile Tyson unpack his stuff and he sets up his equipment from Karai including his radio, which he programs. He hears static and tries it out.

"Hello, mistress." Tyson says to the radio.

"Yes, come in, Tyson." A voice says over the radio.

"I'm here, mistress, and I will find the turtles' Japanese lair."

"Good, where is your signal coming from?"

"My half brother's apartment."

"Why are you at an apartment?"

"Because, mistress, my dad suggested it and according to my tracker the turtles aren't near by."

"They are there, Tyson and when you find them you will find their allies the Spirit Detectives and the portal to the Dark Realm."

"Yes, Mistress."

Tyson starts checking his other equipment. Meanwhile Yusuke is at his restaurant waiting for the other spirit detectives and the TMNT to come with the ally that the TMNT have gained. Kuwabara comes first and orders what he wants. Kurama comes next with Hiei behind him. The TMNT comes five minutes later with half demon chipmunk the Spirit Detectives don't recognize. Yusuke makes everyone a meal to eat. Yusuke makes himself a meal as well.

"Took you guys long enough." Yusuke says teasing the TMNT knowing they got back from New York City.

"Well, our new friend is new here to Japan." Raph says patting the half demon chipmunk on his back. "We wanted to be a surprise to for our new friend to meet you guys."

"You guys know the famous Spirit Detectives!" The half demon chipmunk utters out surprised. "You guys are…" The half demon chipmunk faints.

"Did your friend just pass out?" Kuwabara asks confused looking at the half demon chipmunk.

"I think he did." Mikey answers Kuwabara looking at his new friend on the ground. "Wake Up, Rods!

"Huh? Sorry!" Rods say embarrassed.

"So this is Yusuke, Kuwabara, Kurama and Hiei." Mikey introduces pointing to each Spirit Detective. "Guys, this is Rodney, Rods for short."

"Wow, nice to meet you guys."

"You too, so guys, what's going on with Foot girl?" Yusuke asks seriously to TMNT.

"We don't know exactly but it has something to do with Demon World or what she calls the Dark Realm." Don answers seriously.

"She's looking for some power source to make her powerful." Leo tells the Spirit Detectives.

"Did she describe this source?" Kurama asks seriously.

"No, she didn't but she did shoot a laser toward Japan." Raph answers seriously.

"On a mission for Koenma, we saw a beam hit near Demon's Door Cave." Yusuke explains to the turtles.

"The Demon's what cave?" Raph asks confused.

"Explain later, Raph."

Raph asks the Spirit Detective to explain about Demon Door cave. Kurama explains that where the portal to Demon World is. The Turtles are in shock. Rodney is confused, but he sits there and listens attentively. Leo asks if that's where they fought Sensui. Yusuke answers yes. Hiei tells the turtles the portal to Demon Door Cave was closed off by Enma's SDF members. Don realizes and says that Karai just opened the portal back open with Rodney's powers.

The Spirit Detectives are in shock and they look Rodney. Rodney looks at Spirit Detective confused. Kuwabara asks if Rodney has all that power in his small body offending Rodney. The turtles answer yes. Mikey explains that Rodney is half demon and half human. Rodney interrupts Mikey and tells the Spirit Detectives about his power drain every time he uses most of his power. Kurama explains to Rodney that he has no control of his demon energy. Mikey excuses Rodney to inform about Karai and her new people.

"She's got new sidekicks that kicked our shells." Mikey says seriously.

"Who are they, Mike." Kuwabara asks seriously.

"Well, one is a tiger mutant and the other is a mutant/demon lizard."

"Well, if they come here, we'll kick their asses." Yusuke says seriously. "Well, I gotta go, my half brother's home and probably has made a mess by now."

"Half brother?" Mikey asks in shock with others looking the same way.

"Yes, half brother, I never told you guys because I haven't seen him in years."

"Well, that's the shock of the day." Mikey says as the others nod in agreement.

"I tell you guys later." Yusuke says hurrying off to his apartment. What he and the others don't know that someone is watching them from a distance.

Yusuke gets back home to his apartment. He opens his door and walks into his kitchen to find Tyson making a snack for himself. Tyson stirs his snack up and he tries to make his snack. He curses to himself not remembering how it went. Yusuke laughs a little making Tyson notice him. Tyson turns around annoyed with his snack facing his big half brother who has a teasing smirk on his face.

"Need help, bro?" Yusuke asks teasingly to Tyson who is still annoyed.

"No! I know what I'm doing." Tyson answers annoyed.

"Ok, but you're doing that wrong, little bro, making rice balls takes practice."

"I know how to make a rice ball, bro. I'm not that inexperienced."

"Ok, whatever."

Tyson continues to make his rice ball still doing it wrong. When he finally puts it together it fall apart making Tyson mad. Tyson curses angrily knowing Yusuke was right but he didn't want to admit it. Tyson looks around for Yusuke. He finds Yusuke in on his couch asleep. Tyson smiles teasingly knowing he has a plan. He goes to find balloons in his room and fills them up with water. He gets a ladder out of his bag and hangs the balloon over Yusuke. He drops it. It splashes and hit Yusuke in the face making him wake up with his hair down and his face wet thinking he is drowning. Tyson laughs at Yusuke.

"Damn it, bro, what the hell was that for?" Yusuke yells out angrily with his face red.

"Just having fun bro!" Tyson says teasingly.

Yusuke growls angrily but sees Tyson's hidden stash of water balloons. He smirks mischievously, leaps over the couch and grabs a water balloon and throws it at Tyson making the teen get wet with his own ruffled hair fall down like Yusuke's. Tyson growls and throws more balloons. Yusuke and Tyson keep throwing balloons until they both are tired. Yusuke yawns and he carries his little brother to his room. He puts Tyson down on the bed. He leaves the room and goes to bed in his own room. It is in the morning when Tyson wakes up as hears his radio and he sees he is in his bed. He goes to his radio. He hears another voice over the radio.

"So, brah, are you in town yet? I mean come on, I've been here waiting for three days!" The voice calls annoyed but whining.

"I'm here, asshole, so stop your whining!" Tyson groans annoyed of the person on the other end.

"Hey, hey, I'm been here since the damn turtles move in with Rodney Hawk. I've seen them with some guys yesterday."

"Ok, Adonis, keep a look out for them. Tell me so I can find their Japanese lair."

"Sure, brah, be careful though I heard the guys they are with are pretty strong."

"Don't worry I'll kick their asses whoever they are."

"Ok, Adonis, out."

Tyson puts his radio down. He goes out to living area and sees Yusuke making breakfast for them both in the kitchen. Tyson sits down at Yusuke's counter. Yusuke hears Tyson and turns around and gives Tyson the rice ball Tyson tried to make last night. Tyson smiles and thanks his brother. Yusuke serves breakfast.

"Well, that was fun last night!" Yusuke says as he puts his breakfast in mouth.

"Yeah, it was, hey bro, I have to go work today. I'll be back later." Tyson says as he eats his breakfast too.

"Ok, I'll be gone in the afternoon. So if you come back the key to my apartment is under my mat, ok."

"Ok."

Yusuke and Tyson finish their breakfast. Tyson leaves with his equipment in his bag. He tells Yusuke good-bye and Yusuke says the same. Tyson start walking to a warehouse and he goes in and meets…

To be continued…