Notes: Emerging temporarily from AO3 to post this here on FFnet. There are surprisingly few fics for Rikuo/Tsurara (or really, for the fandom in general despite being relatively popular). It's one of my favorite OTPs from one of my favorite mangas, so I guess I might as well contribute. XD There's also a hefty bit of Rikuo introspection because of the way Day Rikuo and Night Rikuo operate. More in the End Notes.

It's taken a long time for Rikuo to come to terms with the youkai blood running through his veins. He's mostly human rather than mostly youkai; his grandfather and father have lived with this constant fire every waking moment. The blood in him stirs to excess, towards a kind of arrogance – he owns the world and his hyakkiyakou. Whatever opposition he encounters, he'll either bend to his will or conquer. It's a confidence enough to take on the entire spirit world, a pride enough to make him the rightful heir of Nurarihyon and the Master of all spirits.

The youkai blood sleeps during the day, submerged but never entirely out of reach. At night, his senses sharpen and ignite the world into shades of black, of fear.

Gyuuki and the others have asked him more than once what it's like when he shifts, whether Night Rikuo is any different from Day Rikuo. He doesn't laugh them off but he doesn't exactly tell the truth either.

To be honest, he's not sure if it's something he can explain.

Both Day and Night are his aspects. He is Nurarihyon, so he is a flower reflected in a mirror and the moon floating on top of water.

He is two boys, a young youkai lord lounging in a cherry blossom tree and the human boy standing below.

When the water ripples, their places exchange.

His blood is banked, like burning embers. His blood is on fire.

The more time passes, the more he becomes the moon on water. There is less division between Night and Day because both are him. The blood he'd rejected during his elementary school days has seamlessly merged within him, as it had in the days when he'd toddled after his grandfather in hero worship. He feels more himself with every passing day, month, year.

Night falls. His hair lengthens, his body changes minutely. His perfect eyesight sharpens further; if he concentrates hard enough, he can see the crystalline lattice of a falling snowflake. The fire within him transforms the midwinter chill that was already negligible to his 'human' body into a cool breeze.

It's been three years since the battle against Abe no Seimei at the Spiral Castle. It's becoming less and less of a transformation whether the sun rises or falls.

Rikuo doesn't know whether he should be grateful that none of his hyakkiyakou have commented on this development. He doesn't know what's worse, that his hyakkiyakou know and haven't commented to spare his feelings or that they haven't noticed any change yet but will definitely ask him once they realize what's going on.

Both are pretty terrible scenarios and they make him stupidly depressed.

He heaves a sigh and reaches for the sake, taking the shallow cup rather than the bottle. He's been scolded by Tsurara already for doing that outside of their raucous celebrations.

"What was that sigh for, Rikuo-sama? It's a beautiful night!" Tsurara looks towards him, puzzled. Her face is fresh and bright, and her cheeks pink with enjoyment. Looking at her like this, she really is a Yuki-onna to be enjoying the cold so much.

"I've said this before, but things go really well for you in the winter, huh?"

"Mmhmm!" she nods happily.

Just when he thinks she's going to back off, she leans closer instead. "What's on your mind?"

He takes another sip. It's useless to pretend nothing's wrong because he knows Tsurara will drag it out of him one way or another. One time she'd even gotten his mother involved. All he can do is avoid answering for as long as he can.

He's avoiding not only because he doesn't want to talk about it. Tsurara is important to him and he cares about her answer more than he should. The unsaid feelings running between them have been building for a long time now, beginning so far back that he doesn't even remember when it started. He can't stand her rejection.

"I've changed," is all he says. What he doesn't say but he trusts her to understand: the human and youkai in me is no longer as simple as a transformation.

What he doesn't say but dreads: I don't want to be accepted better as the leader because I look more like a youkai now than the human that is still a part of me.

"Rikuo-sama is Rikuo-sama no matter what!"

His face slackens in surprise for a moment. Tsurara is smiling at him – beaming, really – in that way of hers, as though she's seen all of him. There are no smoke and illusions with her, no matter how he hides.

"I've lost, huh," Rikuo mutters to himself, smiling somewhat ruefully. With just her words, it feels like all the weight is gone.

"Eh?" Tsurara tilts her head in confusion.

He kisses her.

When he draws back, her face is frozen. He waves a hand in front of her experimentally. It's kind of funny, actually. Also, cute.

He goes in for a second kiss.

By the time he gets around to incorporating a little tongue, Tsurara's brain has finally caught up to the situation and she scooches backwards rapidly, hitting her back against one of the wooden pillars lining the porch.

"Eh-uwawawah?!" she says, entirely red and flustered. "R-Rikuo-sama?!"

"I like—no, I love you," he says. "I think I've made it pretty clear."

Contrary to his bold words, he feels his face heat up and he turns to the side. Ugh, it's so embarrassing.

But when she laughs, he has to look back at her. One of her sleeves is raised decorously to her mouth as she tries to stop, her eyes nearly shut with the force of her mirth. She looks completely delighted and so bright that he thinks he's going to go mad.

"Rikuo-sama?" she fidgets, blushing a little when she notices his stare. "Why are you looking at me like that?"

He reaches out a hand, cups her cheek. Her skin is so soft, growing warmer when he brushes his thumb over the bridge of a cheekbone.

She bends easily towards him when he draws her into another kiss. Their lips brush and their breaths mingle. It's light and almost tentative but it feels like his blood is burning in an entirely new way every time they touch.

"You're my woman from now on," he murmurs, pressing a light, close-mouthed kiss at the corner of her mouth. It's more of a statement than a question, staking claim.

He can feel her lips curve into a smile this close, feel the huff of warm laughter.

"Yes," she says, before declaring a little proudly and mostly tenderly, "Rikuo-sama is mine too, right?"

"What do you think?" he asks rhetorically, but the way he holds her steady and close tells her what he means to say.

End Notes: I absolutely do not buy that 'Night Rikuo is different from Day Rikuo' business. I don't. In early bits of the manga, before Rikuo went full-on 'I hate youkai' you see him shift into youkai mode without that 'I am two people' scene. He simply shifts, and you see him commenting that it's like his blood is on fire. Plus his dad Rihan, who also has mixed youkai-human blood, is always himself and never two people.

This leads me to believe that his early rejection of his youkai blood led to an unnatural state – kinda like split personality disorder except way unhealthier, like ignoring the fact that the left side of your body exists. It's something that I believe is gradually resolved or at least alleviated during manga canon when he finally accepts both sides of him. He can actually remember the battles that occur when his youkai blood takes over. During the Thousand Tales arc when Rikuo is in youkai 'offensive' mode, he acts more like his usual self. Tsurara even comments that he's missing the usual 'whooshiness.' In the endgame (probably after manga canon), I think Rikuo's going to end up like Rihan. Both his mind and body are going to acclimatize and adjust into a permanent in-between state. He's still going to pass out or get tired if he overdraws on his youkai powers though, like how Rihan got overly tired after using Matoi too much. Neither of them are full-on youkai.

Some people may cite one of the ending omakes, the one when Rikuo gets drunk on Youkai Goroshi as an example of his two selves but I disagree. I think he was just incredibly smashed. How many of us have perfect recall of events after a hard night partying?