Half-Step Mangekyo

As evening approached, Uchiha Ao sat at his desk, staring at the five vials before him.

The rays of the setting sun slanted through the window lattice, casting mottled light and shadows across the wooden table.

He didn't know what had gotten into Sister Izumi tonight; for the first time ever, she hadn't come running to cuddle with him, choosing instead to go out and train.

Fortunately, she was still training within the clan grounds rather than heading elsewhere.

Otherwise, he would have abandoned his plan to fuse with Shisui's bloodline tonight and instead followed her in secret to ensure her safety.

"Success or failure hinges on this!" The simplest way to fuse bloodlines was to swallow the blood directly.

"Gulp."

As Shisui's blood slid down his throat, a gentle, warm sensation rose from his stomach, as if a current of heat were slowly circulating through his meridians.

He could clearly feel Shisui's power merging with the Otsutsuki Bloodline within him, spreading and permeating like a drop of ink dissolving into clear water.

Uchiha Ao's eyes began to glow faintly, and the patterns of his Sharingan started to shift quietly.

The original three tomoe rotated slowly, their brilliance intensifying, and the lines between them grew increasingly complex.

[Ding, Otsutsuki Bloodline progress 11/100]

[Ding, Otsutsuki Bloodline progress 12/100]

As the system notifications chimed one after another, the Otsutsuki Bloodline progress bar kept jumping, and Uchiha Ao felt an invisible power swelling within his body.

His skin turned pale as snow at a visible rate, drained of all color as if all vitality had been sucked out, taking on the cold, sharp texture unique to the Otsutsuki clan.

"Hah. A pity, still just a little short." Uchiha Ao panted slightly, raising a hand to wipe the fine sweat from his brow. He had expected this fusion of Shisui's blood to awaken his Mangekyo, but it seemed he was still a hair's breadth away.

Could it be that I'm missing Sasuke's blood? No, it should be Indra's. Uchiha Ao thought silently.

If one were to ask who the progenitor of the Uchiha clan was, it would undoubtedly be that first fellow seduced by Black Zetsu—Indra, one of the sons of the Sage of Six Paths.

"It seems I'll need to find a way to get Sasuke's blood."

Just as he was deep in thought, footsteps suddenly echoed outside the door.

Accompanied by a faint "click," an excited voice came from behind him.

"Little brother! Let Sister give you a hug!"

Uchiha Izumi burst into the room, still radiating the heat of her training, with tiny beads of sweat clinging to her hair.

Oh no! Uchiha Ao cursed inwardly. He was well aware of the changes in his body; this appearance would surely worry Sister Izumi.

Damn it, can't I change back?!

Uchiha Ao screamed frantically in his heart.

He thought of using a Transformation Jutsu to fool her in an instant, but before he could even act, his skin tone reverted to its original state.

"Little brother, Sister is so tired, let me have a hug." Uchiha Izumi, completely oblivious, lunged forward and buried her face in Ao's shoulder.

Uchiha Ao stiffened for a moment, and only when he felt Izumi's arms tighten around his waist did he slowly relax, though his heart was still pounding violently in his chest.

"Sister Izumi, go take a bath before hugging me! I just finished washing up, and you're getting me dirty again." Since his physical changes hadn't been noticed, his worries vanished, and he tried to push her away with a hint of feigned annoyance.

However, there was no reaction from her.

"Hmm?" Uchiha Ao turned his head in confusion, only to see Izumi's hair hanging down to cover her face, and the weight on his shoulder made him realize something was wrong.

He carefully supported her back and gently straightened her up, only then seeing the undried tears clinging to her eyelashes. Her damp cheeks were flushed with an unnatural redness, and her breathing was shallow and rapid; she had clearly fallen into a deep sleep from sheer exhaustion.

Uchiha Ao carefully wiped the tears from Sister Izumi's face, then gently carried her to his bed.

After settling her in, he hesitated for a moment before kneeling to remove her dust-covered training shoes.

Beneath the surface of the shoes, a pair of fair ankles were slightly red, clearly the result of long, high-intensity training.

Uchiha Ao felt his throat tighten and his palms grow damp. Even though he only wanted to check if she was injured, his gaze uncontrollably lingered on her toes.

"Little brother, hug..." Uchiha Izumi muttered in her sleep, still calling for him.

Uchiha Ao snapped back to reality, then abruptly pulled the quilt up to cover her tightly, leaving only her head exposed.

Afterward, he ran to the bathroom to wash up.

Once finished, Uchiha Ao quickly dried himself and changed into clean clothes.

Returning to the room, he found Sister Izumi sleeping comfortably, her steady breathing echoing softly in the quiet space.

Uchiha Ao's heart settled slightly, but the thought of her crying made him feel incredibly angry.

Damn it, I've never even made Sister Izumi cry. Which bastard dared to do this to her!

Hmph, Itachi, Obito, you two are finished!

Having added another tally against those two in his heart, Uchiha Ao felt his body and mind ease significantly.

He tiptoed out of his room, pulled the door shut, and stood in the hallway, looking around with a dazed expression.

There was just one problem: where was he supposed to sleep tonight?

After standing in the hallway for a long time, Uchiha Ao decided to head to Sister Izumi's room.

Pushing open the door, a faint, natural fragrance wafted toward him.

It was a unique scent, clean and refreshing, like honeysuckle soaked in morning dew.

The room's furnishings were simple to the point of being austere: a hard bed occupied most of the space, with the bedding folded as square as a block of tofu, a kunai glinting with a cold light pressed against the corner.

It was worth noting that Uchiha Ao discovered the bed was covered in photos of himself.

Uchiha Ao picked up a few at random, intending to see what he looked like before, but unexpectedly discovered another secret.

Fine, fine, fine. So it turns out I've been stalked by Sister Izumi this whole time.

The angles of the photos were ridiculously tricky, making him wonder if Sister Izumi had specifically trained for this.

After tidying the photos to one side, Uchiha Ao lay down on the bed.

The scent of honeysuckle lingering in his nostrils became even more distinct, yet for some reason, while the fragrance was elegant and pleasant, it still couldn't compare to the rich scent on the bed in his own room.

Uchiha Ao's mouth twitched.

Good grief, she probably spends more time sleeping in my bed than she does in her own!

Despite this thought, he tucked himself further into the covers. Accompanied by Sister Izumi's familiar scent, Uchiha Ao slowly closed his eyes, his breathing gradually deepening.

In the middle of the night, Uchiha Izumi turned over in a daze, habitually reaching out to grab something, only to grasp at empty air.

She snapped her eyes open, and the Three-Tomoe Sharingan instantly ignited with a scarlet glow in the darkness. Surprisingly, the patterns between the tomoe began to twist and reorganize, the crimson light growing increasingly intense.

A surge of powerful ocular power erupted from her body.