Yep its a seal

"Oh god.", Temari whispered in realization as the piece to the puzzle in her head was staring back at her in plain view. His insane stamina and chakra limit, how he seemed to have wanted to kill the Hyuuga in the prelims after he had injured his cousin, the way the villagers had been acting around him the whole time they had been seen together. It all made sense. "You're just like him... you're another one!", Temari whispered, backing up from Shisui as he gave her a calm look but one could tell on the inside Naruto was anything but,

"You... you have something inside you, don't you?", Temari asked

Shisui didn't know what she was talking about "Temari what are you talking about"

"that mark on your arm is a seal" temari says

"a seal i thought it was a weird looking birthmark" Shisui said

"no it's a seal of a tailed beasts" temari said. (just like naruto and Gaara) Shisui thought. Temari rested her head against his back tears welled up in her eyes, "Shisui... I need you to do something for me... only you can help me... please.", Temari said as she looked up at him with a pleading look

"of course i will" Shisui said. Temari hugged him tightly as she told him everything she knew and that the sand and sound village where going to attack the leaf village during the exam

When Temari finally separated herself from him, she smiled as she said "I think you better get going Shisui. Temari said as Shisui nodded.

"Um...Temari", Shisui said as she silenced him kissing him on the cheek.

Shisui eyes widened when that happened as he held his cheek and asked "Temari, what was that for?".

Temari smiled. "For proving everything I have believed was true about you.", Temari said before smiling and then she disappeared in a flash of speed. Shisui went to the Hokages office and told him about the sand and sound villages plans to attack the leaf. what seemed like forever Shisui Finally began the trip back towards his house,

Shisui got back home to his house and first decided to take a shower. As he undressed, he figured he should get a change of wardrobe anyway, since after the month of training, he was basically wearing rags. As he got out from the shower, Shisui felt Anxious and ready for the exam. Shisui decided to go check on Kankurō. When he opened the bedroom door to Kankurō's room he saw that she was asleep at his desk a bunch of schematics piled everywhere he decided to surprise him when he wakes up and sees him. Shisui spent the hole next day with Kankurō improving Kankurō's Puppets.