A/n: another trope y'all seem to like is reader or L being an idol and the other being a hardcore fan. So here's one of them.

Prompt: Light takes Sayu to her favourite singers concert. Turns out his rival is there.

"WHAT? NO WAY! LIGHT YOU'RE THE BEST!" Sayu exclaimed, looking down at the tickets she's just pulled from her birthday card.

"I knew a concert like this wouldn't be mum and dads scene so I thought I'd take you" he replied.

She hugged her brother in return, squeezing the life out of him.

"You're literally the best brother ever. You better dress up with me!"

"I mean I guess..."

He and Sayu had the whole day to figure that out. The concert started at 8 and went until 11, as almost the whole discography would be played.

(Y/n). Last name unknown. That's who Sayu had plastered all over her walls, wore shirts of, had countless CDs of. You were decently big, not quite a household name yet, but you were able to pack out arenas. Your current era was themed around the glamours life of an old fashioned starlet. Long dressing gowns, silk clothes, heels, red wine, velvet sofas and bright lipstick. Your songs, when put in the right order told a story. At this point in the story the character was in a lot of spotlight and lived a glamorous life, but the undertones of the songs suggested a tragedy would happen next album.

Your concerts involved a lot of audience participation. Fan chants, costumes, having the crowd hold up a runway to the B stage, going up to the front row and having people sing into the mic, the whole nine yards.

"Wait- no that doesn't fit the theme..."

"L it'll be fine"

L looked at the two pairs of sunglasses, trying to decide what ones to take. He wasn't going to show up to his front row mosh pit concert without wearing the right outfit. This was the one event he was actually going to put effort into his look, he was such a big fan he wouldn't dare go against the unwritten dress code. He also planned on bringing flowers to toss onto the stage.

"Uhh... the black ones they'll go with the coat..." he decided, placing them on his head.

Grabbing his phone, keys, wallet and tickets he stuffed them all in his pockets.

"Ok, I gotta run. If I don't get a good spot in line I'll have to fight someone for the front row"

Watari have him the dad seatbelt arm ams stopped him running out the door.

"Forgetting something?" He said.

L gave him a confused look for a second before it clicked.

"OH- water bottle. I'm not dying of dehydration, I could miss song of the dead socialite-"

Running back down to hall to grab said water bottle, Watari laughed. Every time he's gone to one of your concerts he's been truly alive with joy. An uncommon sight to see with L. And of course, there was no way he'd miss his favourite song due to dehydration. In fact, Watari wouldn't be surprised if he did pass out, and the second that song started playing he'd immediately wake up.

"Ok, I'm going" L said.

"Be safe"

"Yeah yeah, if you hear screaming from a mile away that's me because she made eye contact with me"

Heading out the door, he rushed for the train to get there as early as he could.

The day seemed to drag on for L and Sayu. So when the sun started to set and the arena began to light up and the lines got longer, the buzz of excitement that'd been building all day was practically making them vibrate in anticipation.

Sayu watched the mosh pit line finally be let inside, waiting for general admission doors to open.

"Come on! It's part of the aesthetic!" She said.

"You're not putting lipstick on me Sayu" Light said.

Sayu had a managed to get Light into clothes that fit the theme, but getting lipstick on him was another battle.

"Plleeeasssee! It's like her signature. You have to, it's my birthday"

Light sighed, knowing there's no convincing an exited Sayu.

"Fine..."

Just as Sayu finished up putting lipstick on her older brother, the GA doors opened and tickets starting getting checked in.

"Oh my god, it's happening-" Sayu squealed.

"Save the cheering for the concert"

"You're right I gotta preserve my voice before I loose it!"

After a little while longer of moving through the line, they made it inside the area. When the entered the seating area, the room was hazy with smoke and red lights, there was a velvet sofa, a dressing table and bed with a canopy and silky sheets on the stage surrounded by lights on the floor. A red carpet sat off to the side rolled up for the stunt where you'd walk over the crowd. The ambiance music was the sound of a record player playing soft songs and the waves of a beach crashing. Even though Light wasn't a fan, he was impressed with the set up. He didn't dislike your songs, just wasn't as obsessed as Sayu was.

Their seats were only a few meters away from the confetti canons, so he knew Sayu would be trying to catch as much as she could to take home.

They had a good view, now too far back but not right up the front. The mosh pit was buzzing below them, it was massive. People were bouncing a giant beach ball over the crowd, everyone was dressed to the theme.

Once the crowd was all packed in, the ambiance changed to the opening of the first song and the lights started to move. The crowd immediately went insane.

As the lights were directed at the crowd and not the stage, you snuck on in the dark and got under the blankets of the bed ready to make your entrance. You saw the spotlights shine on you behind your eyelids and heard the crowd yelling and the music get to the first verse. Starting to sing, you sat up, throwing the blankets off and getting up to face the crowd.

The show now officially underway, there were 3 hours of pure music and adrenaline for both you and the crowd.

As the concert progressed, Light was actually throughly impressed with the show. All the transitions were smooth, the energy of the crowd was amazing, and even though every two seconds he would hear Sayu scream, he could heat every little detail of the music. From lyrics to backing drums.

He held his breath when he watched your walk over the crowd to the B stage and back again, when the beach ball made its way to he and sayus seats he jumped for it. The stunts where you'd disappear from the stage and show up somewhere else in the arena genuinely had him on the edge of his seat wondering were you'd appear. Surprisingly, he was really enjoying himself.

Getting to about the half point of the concert, the stage setup had changed, the lighting colours had shifted and the low strumming off a guitar was playing as the crowd cheered.

"Oh my god! Oh my god! The song of the dead socialite!" Sayu exclaimed, getting even more exited if that was possible.

Light knew this song too well, Sayu played it all the time. It was definitely her favourite.

About the character finding out a socialite had died and getting paid to replace her in the spotlight. It was a sad but glamours song meant to talk about how corrupt Hollywood could be.

Famously, you'd walk around the front row and get people to sing for this song.

The cameras projecting onto the screen followed you as you sang and jumped off stage, roaming the front of the stage looking for someone to sing in the crowd. You spotted a bouquet of roses in the hands of someone at the front bar, your eyes following the arm up to the person. A boy with black hair and sunglasses on his head, a sheer shirt and black coat topped up with black lipstick was singing along. You knew the look he was recreating. You wore the girl version of that outfit in your 'sold my soul' music video. Although, you wondered if the black tears were something deliberately done to recreate the look or if he'd just been crying the whole concert and ruined his mascara.

Either way, you were going for him. The camera followed you as you walked up to him, when he realised you were going for him he reached over the front bar to hand you the roses.

You got to him, placing your hand atop his on the Roses. He looked so happy, it made you smile. 

"Glitz and glamour six feet under, the curtain dropped on miss socialite-"

You pointed the mic at him.

"The show must go on, the money rolling in. I feel bad but that's just showbiz baby"

Meanwhile, Light starred at the screen in utter shock. There's no way...

"Holy fucking shit-" he said.

"What?" Sayu replied.

"I KNOW HIM! WHAT THE-"

"You know him?"

"He's-"

Light cut himself off. About to say L. He couldn't do that, it'd reveal he had comments to L therefore, Kira.

"He's the one that tied with me in the entrance exams!"

"What? No way! That's so crazy" Sayu laughed.

Light just watched in disbelief as you and L had a moment signing into the mic together over the front bar clutching a bouquet of flowers. Firstly, L liked this kind of music? Secondly, he'd never seen L in clothes that aren't blue jeans and a white shirt. Thirdly, he'd never seen L emote before. And finally... was he wearing makeup?

Also... since when could L sing so well?

He was in such shock he didn't even notice the next song had started and you'd gone back on stage until halfway through.

L smiled, half crying half buzzing in joy as he watched you take his flowers back on stage. He could hardly believe that just happened. He felt something in his hand, he didn't realise until know because of all the excitement of being picked to sing. Whatever it was it could wait, he'd hold onto it until the concert was over.

When the concert finally ended, confetti finished raining down on everyone and your walked off stage, the birthday girl and her brother walked back outside into the night air.

"Man that was amazing! I'm so tired though" Sayu yawned, clutching the bag of confetti she'd collected.

"We can head home in a minute, I gotta find Ryuzaki" Light said.

They headed around to the mosh pit entrance where people were walking out talking about the concert. He spotted L, who was standing there in utter shock holding something in his hands, a bag of confetti and half empty water bottle held under his arm.

"Ryuzaki!"

He didn't look up as Light and Sayu approached.

"Ryuzaki, since when were you into (y/n)?"

He didn't reply again.

Light looked over his shoulder at what he was holding. A paper.

I've kept this paper since my first concert waiting for the day I saw someone as beautiful as you to give this too. As long as you don't leak this, I'm sure we can be friends.

555-25393

-(y/n) xxx

"Holy shit-" Light said.

"What's going on?" Sayu asked.

"That's her number..."

"Her WHAT-"

L sighed, pure shock in his eyes.

"Light..." L began.

"Yeah?"

"I'm gonna fucking pass out-"