inspired by ghost hunt and my love of all things supernatural. this might turn out to be arco27, just warning. but either way, it will involve a positive relationship between the arcobaleno and tsuna. unfortunately, the other guardians will not be playing that big of a part in this one.

the title is based on the fact that inquiry is a synonym for investigation, and also the IB ost named Inquiry.

ft. Aria, not Luce, as part of the Arcobaleno group. Luce still plays a part though

How in the world did this happen?

The boy ran through the school corridor. Was it always this long? The path seemed to stretch out for forever. No matter how much, how fast he ran, he could never see the end.

The pitter-patter of footsteps behind him grew louder and louder. He couldn't let her catch up to him. He had to run away. He had to hide.

He could feel her chilled breath on his neck, the grotesque stench from her mouth almost overwhelming his senses. With every second that passed, the temperature around him became colder and colder.

An uninterrupted stretch of pale cream walls on one side, windows overlooking a inky black world on the other. There was no place for him to hide.

I never meant for it to be this way!

Suddenly, he saw a door and hope blossomed in his chest. With a desperate burst of speed, he sprinted into the room and slammed the door behind him, locking it. He could hear scratching on the other side of the door but, to his relief, the flimsy wood never gave away.

Soon, the scratching subsided and the boy slowly backed away from the door. His breathing began to even out when he bumped into something wet. His heart rate immediately doubled in speed as he slowly turned his head.

A bloated, grotesque face entered his line of sight, smiling with its mouth wide open. Its teeth were black and green and half of them were missing. Cold puffs of breath blew into his face, stinking of stagnant pond water and dead fish. The boy trembled as long, wet, clumps of dark greenish black brushed against his cheek. The face leaned closer to the boy.

"I've found you, my love!"

He screamed.

-o-

Afternoon, Saturday.
Moriki High School, Class 1-A.

Tsuna's seat was behind Akiyama's and therefore, even though he wasn't very close to the boy, Tsuna was constantly reminded of his absence.

It had been three days since Akiyama had gone missing. The police had come in to investigate but there was no evidence of… anything. It was as if Akiyama had simply just disappeared into thin air.

Of course, that only served to fuel the rumours.

"He was taken, wasn't he?" Tsuna heard a girl whisper to her friend. "By the nure onago."

"Really? Wasn't it because of the child in the computer lab?" her friend replied.

"I'd rather think it was the nure onago," the girl confessed. "It doesn't target girls so I feel safer that way."

A few weeks after Tsuna had started his first year at Moriki – having moved from Namimori into the area after his mother passed away – rumours of the school being haunted started. At first it was generic things like a ghost in the last stall of the girls' toilet, or an invisible dog prowling the school at night (which scared Tsuna more than any ghost, to be honest). Those were stories one would hear in any school.

Then it evolved into hearing voices in the computer lab and having something touch your legs in the science labs. When it was raining so heavily that you could hardly make out what was a few feet in front of you, you would be able to see someone standing at the abandoned bus stop that was just opposite school. If you talked to them, something bad would happen.

The teachers refused to believe the students who reported the mysterious happenings to them, thinking that it was just superstition. Those things never happened to Tsuna before, and he was thankful for it. However, he was one of the few students who lived in the dorms on the school compound and he dreaded the day he was going to encounter… things.

One day, Akiyama marched into the school and boasted that he had talked to the mysterious person standing at the bus stop. Apparently, it was a nure onago, a woman who had long, dripping wet hair and appeared drenched and stinking of decay or something, and would fall in love with you and follow you around if you so much as smiled at her. He talked about how the nure onago followed him home and he had to get some type of charm in order to chase her away. In Tsuna's opinion, he seemed a little too relaxed to have had encountered something like that.

The few days before Akiyama vanished, Tsuna had observed that he kept looking over his shoulder, as if expecting to see something there. He would shiver often and wrinkle his nose as if he smelled something horrible. Bags appeared under his eyes and his movements became a lot more erratic. That was when Tsuna believed him about the nure onago.

Since Akiyama had disappeared, it had been raining continuously and heavily. People have mentioned that they, too, could see a person at the bus stop. Tsuna played it safe and refused to leave the school campus, barricading himself in his dorm room and living on his own cooking. He dreaded the day he would run out of ingredients.

The school bell rang, signalling the end of school. Before anyone could leave the classroom, however, the class representative stood up and made an announcement. She said something about people who had had encounters with the supernatural meeting someone at the reception room. It didn't really have anything to do with Tsuna so he just stood up and left.

When he crossed over from the main school building to the dormitories, he resolutely looked down at his feet and did not glance at the bus stop opposite the school.

-o-

There was more homework today than usual and when Tsuna was finished with it, he found that it was already twilight. Normally Tsuna wouldn't have been so absorbed in his homework that he lost track of time but ever since his mother died, Tsuna had, well, tried to be a little better at his life in general so that she'd have some peace of mind when she was watching over him. Also, he was desperate to have something, anything, to take his mind off the matter of Akiyama's disappearances and the occurrences happening around school that he had basically threw his entire soul into finishing his homework with a single-minded determination.

Tsuna hadn't bathed yet and the bathroom on his level was just down the hall. It wasn't very far away, considering that he was the only one staying on that level and hence he could pick wherever he'd like, but in the light of recent situations, even the short trek to the bathroom seemed daunting.

The sun was nowhere in the sky, but a faint light still shone from the horizon, casting the entire world in a strange shade of pink and orange. All Tsuna could see were solid black silhouettes and he took a few minutes to debate about whether he wanted to gather his courage and bathe, or if he wanted to just shut himself in his room and marinate in the filth he had accumulated throughout the day. In the end, he decided that hygiene was more important.

He grabbed his flashlight before he left his room.

-o-

Tsuna finished bathing in less than five minutes. He rushed out of the cubicle he was in and ran straight into something. He stiffened.

Why was someone in the bathroom when Tsuna was literally the only living human being on this entire floor?

Slowly, Tsuna brought his gaze up to see long, wet, black hair. And he stopped, heart leaping into his throat. In his utter terror, he did not notice that the person in front of him was not a woman and his hair was merely damp, not dripping wet. There was also an absence of pungent smells. However, nothing was going into Tsuna's head and all Tsuna could see was Akiyama's description of the nure onago.

"I DON'T WANT TO DIE!" Tsuna half screamed, half sobbed as he continuously swung the flashlight at the person in front of him.

"W-wait! There's a—! Misunderstanding!" the person yelped as he tried to dodge Tsuna's attacks. He slipped on a wet spot in the bathroom and fell awkwardly onto his leg with a muted 'thump'. Tsuna took the chance to dart out of the toilet and scampered back to his room, slamming the door shut behind him and locking it. He then dove into his bed and pulled the blankets over himself, clinging onto the childish belief that it would protect him from any and all evil forces that were lying in wait to kill him.

-o-

Morning, Sunday.
Moriki High School, Dormitories.

Tsuna was awoken by a knock at his door. Sleepily, he dragged himself out of bed to answer the door. A woman with blue shoulder length hair greeted him.

"Hello, are you Sawada Tsunayoshi?" the woman asked. Tsuna blinked slowly and rubbed at his eyes in order to further wake himself up. Then he nodded at the woman's question. The woman smiled and continued. "Were you the one who assaulted Fon in the toilet last night?"

Immediately, Tsuna was wide awake.

-o-

They were called the Arcobaleno, and they were paranormal investigators. The school had called them in a day after Akiyama went missing. They had very fancy, very expensive, very heavy equipment that were supposed to be able to detect ghosts. They were going to set up the equipment today but Tsuna injured one of the people who were in charge of moving the equipment.

"I'm sorry!" Tsuna apologised profusely. "I didn't know—I thought you were… I thought you were…" Tsuna degressed into unintelligible gibberish.

"No, it's fine! I should not have snuck up on you like that!" Fon told Tsuna. His left ankle was bandaged because he sprained it when he had fallen onto the floor.

"Oh dear, what shall we do without Fon?" the one in the hooded cloak – Mammon, they had called themselves – sighed dramatically. "With one less person, it would be harder for us to carry out our investigation!"

"I'll help!" Tsuna volunteered, his guilt leaving him no other option. Mammon smirked.

"Alright then," they said. "You'll be doing part of Fon's job while he's incapacitated. We won't pay you, but that's obvious, isn't it?"

"Y-yeah," Tsuna agreed, feeling somewhat in over his head at the moment. "That's only fair."

"Oh boy." He heard someone – Colonello, probably – mutter. "The poor sap."

-o-

Sunday, Afternoon.
Moriki High School, Computer Lab 2.

Tsuna had been assigned to the tall man who wore a black suit. Tsuna remembered that his name was Reborn. Reborn looked faintly amused by the entire situation.

They worked in silence, setting up speakers and cameras in various areas of the school, and only spoke when Reborn was telling Tsuna to do something, or when Tsuna had a question about the equipment.

Tsuna didn't only have questions about the equipment but he was a little too intimidated to ask them, especially considering that he had injured someone on their team.

"This is the first time someone has mistaken Fon for a ghost," Reborn commented. It took a while for Tsuna to process that it wasn't instruction but when he did, he flushed red.

"I-I-I I didn't mean to!" he stuttered out. Reborn rolled his eyes and waved off Tsuna's attempts at another apology.

"Yeah, yeah. You've apologised enough. Stop that."

"…sorry. It's just that, I was a little high strung and so I didn't really process that Fon wasn't the nure onago…"

"Wait. Nure onago?" Reborn questioned. Tsuna nodded slowly.

"Yeah, wasn't it mentioned by the students? Akiyama told us that the person opposite the bus stop was a nure onago and that she started following him because he talked to her."

"No, the students didn't mention her," Reborn replied, looking pensive.

"Maybe they were afraid to talk about it. I mean, Akiyama did say that they fed on attention…" Tsuna paled. "Hiiieee! Does that mean she'll come after me next?!"

"No, she won't," Reborn said bluntly. "And besides, a nure onago in the middle of a city? It doesn't make any sense."

"What do you mean?" Tsuna asked. Reborn didn't answer, only grabbing Tsuna's hand and briskly walking back to the dormitories.

"We have to talk to Verde about this."

-o-

"Nure onago appear on nights of heavy rain, near water bodies such as lakes, rivers, and swamps. There are no such water bodies around the area, not even canals," Verde stated. "Also, nure onago just follow their victim around for life. They are not malicious and do not kidnap or kill people."

"But, well…" Tsuna trailed off as he thought back to the day Akiyama told the class about the nure onago. "I thought that he was lying at first because he didn't seem scared at all. He just seemed like… I don't know. But he wasn't scared. But then! The days before Akiyama disappeared, he started acting like there was something following around and he kept talking about the smell of pond water and fish! He was really scared and… you can't fake that sort of thing."

"I see." Verde adjusted his glasses. "And what was the time lapse between the day he first mentioned the nure onago and the day he started to act oddly?"

"Um… a few weeks, I believe. Um, it started about three weeks into the semester?" Tsuna mumbled to himself, counting on his fingers. "And then a week before today… probably." Verde waited patiently for Tsuna to finish. "Almost four weeks."

"Hm." Verde contemplated the new knowledge. "That—"

Whatever he was about to say was interrupted by a scream from one of the monitor speakers. Verde immediately directed his attention back to the monitor screams to see that one of the cameras had lost its video feedback and was now displaying static. Its audio feed was still working, though, and Tsuna could hear the sound of a dog growling. Verde was speaking rapidly into a walkie-talkie.

"Hello? Skull? Are you there? Over."

There was a crackle and then Skull's voice came through.

"Verde? There's something here but I don't know—" His voice was abruptly cut off. Verde tried to reach him again, but to no avail. Reborn snatched the walkie-talkie from Verde.

"Lackey, you'd better answer me right now or the consequences will be… unpleasant. Over."

There was still no answer and Reborn seemed a little worried. The walkie-talkie suddenly crackled again but it was Lal who spoke.

"He was at the sports field, wasn't he?" Lal said. "Colonello and I will go look for him. Over."

"You do that. Over." Verde took the walkie-talkie back from Reborn's hands, an annoyed look on his face. "You have your own walkie-talkie. There is no reason for you to take mine."

"Whatever." Reborn stood up. "Tsuna and I will go measure the temperatures in the rooms." He started to walk out of the room.

"But, what about Skull?" Tsuna asked. Reborn shrugged.

"He's not helpless. And besides, Lal and Colonello are enough backup for him." Reborn tugged his fedora down a little so that the rim cast a shadow over his eyes.

"It was the demon dog, wasn't it?" Tsuna said. Reborn nodded and Tsuna looked at his feet. The dog had never shown up in broad daylight before, what had caused it to change?

Tsuna rubbed at his chest to assuage the heaviness in his chest.

He had a bad feeling about all of this.

this might become arco27 depending on feedback.