Work Text:
Senku sat on the floor with several open folders around him, flipping through a stack of paperwork in his lap.
He had been quiet for a while now, but Gen could hear the processing sounds from across the room. Quiet muttering, pages shuffling and that little humming noise Senku made when he was thinking too fast again.
Finally Senku sat back, rubbed his eye with the side of his fist and said it like it was just another stray thought.
“Gen? Why aren’t we married?”
Gen blinked once, then looked back at his laptop. He didn’t respond right away.
Senku didn't seem to expect an answer. His eyes were back on the paperwork. But he was serious, this wasn’t his voice when he was joking. It was genuine curiosity.
Gen closed his laptop slowly and leaned back in his chair.
“Actually, we are.” He said.
Senku finally looked up. His hand froze mid-air.
“...what?”
“We are married.” Gen said again. He opened the drawer next to him and pulled out a document. It was tucked in a plastic sleeve, same as all of their important and serious papers. He just pushed it across the table.
Senku picked it up. “Marriage Certificate.” He read out loud. His voice was perfectly flat. “Ishigami, Senku. Ishigami, Gen.”
He read it. Read it again. Then checked the official stamp.
He flipped the page over like there might be a correction on the back.
Then he looked up.
“How long?”
Gen folded his hands on the desk. “Five years. Six months. Three days.”
Senku stared at him like this information had just flipped his world.
The silence stretched. Senku kept looking at the document. He didn’t speak for a while.
“I signed this.” Senku said.
“You did.”
“I didn’t read it.”
“Nope, you probably didn’t.” Gen replied.
“This was in a pile of boring forms, wasn’t it?”
Gen didn’t even blink. “Mh-hm. Maybe somewhere between taxes and water permits.”
Senku looked at him, his eyes narrowing a little. Not angry, but recalculating.
“You knew I might not be aware of this.” He said.
Gen shrugged lightly. “I thought you might. I also thought you might not. But you signed it and you kept living with me and you let me handle your life for years, so I figured we were fine.”
Senku sat down in the chair opposite him, still holding the paper like it might melt any second. “You married me.”
“Well, you told me to handle the boring parts of civil restoration and legal legitimacy.” Gen pointed out casually. “You said, and I quote, ‘My brain is for science, not for the bureaucratic sludge. Filter out the human junk.’ So I did. It was the easiest way for me to sign your contracts and keep people from bothering you directly.”
Gen went on, just a little softer. “And also because I wanted to.”
Senku leaned back, quietly stared at the ceiling. A few moments passed before he sat up straight again.
Senku read the date for a fourth time.
His voice dropped.
“I’ve missed five anniversaries.”
Gen just shrugged.
Senku dragged a hand through his hair. “You did something every year, didn’t you?”
“Nothing dramatic.” Gen smiled and picked up his mug of tea.
Senku scoffed under his breath. “Yeah, as if. You did a five-star dinner last year around the date, I remember that. And the year before, it was that trip, right? Up to that observatory. You said it was just for watching stars with me.”
Gen didn’t deny it. He just smiled into his tea.
“I needed a break anyway.”
Senku frowned. “We were celebrating anniversaries I didn’t know I had.”
“Well, I got tired of watching you fall asleep at your workbench. You were basically married to the lab again. I figured your real husband deserved some time with you too before I got too jealous.”
Senku stared at the document again.
“Wait. It said Ishigami Gen... and you’ve been signing as Ishigami on all the resource orders. And the zoning requests.”
“Uh-huh.”
“And you introduced yourself as Ishigami Gen to our business partners.”
“I did.”
Senku turned and stared at him. He just noticed what that actually means.
“You really legally changed your name...”
Gen met his eyes. “Yes. You never questioned it when I did.”
“I thought it was a Gen thing.”
“It was a Gen thing. But also a legal one.”
Senku’s gaze dropped and when he spoke again, his voice was low.
“You were famous with that name. In the old world. And you just gave it up?”
Gen gave a small shrug. “You would never give up the name your dad gave you. So I did. It made things easier.”
The words landed harder than anything else had. Senku blinked. Then blinked again, like his brain needed a second try to process it. Gen was right. It was Byakuya’s name. His gift. The one piece of the old world Senku refused to let go of.
Senku laid the certificate down slowly and sat forward
“So that’s why my taxes dropped.”
“Yes. Marriage benefits.”
“And why the housing registry had us listed as co-owners without me filing anything.”
“Yupp.”
“And the health insurance benefits.”
“You’re welcome.”
“You’ve been secretly running my entire personal life.”
Gen raised a hand and spun one finger lazily in the air. “Only the parts you didn’t want to deal with. So... yeah, okay, most of it.”
Senku blinked. “So... have our friends known this whole time?”
Gen just raised both eyebrows.
Senku sat back slowly. “Right. They know.”
Gen gave him a look. “Senku-chan, we live in the same house. We sleep in the same bed. They haven’t heard me go by Asagiri in over five years, what exactly did you think people assumed?”
Senku opened his mouth. Closed it again.
“…Point taken.”
Senku was silent again for a few beats, then narrowed his eyes. “What would’ve happened if I’d read it and said no?”
Gen tilted his head, already expecting that question. “You wouldn’t have.”
“But if I had.”
“You wouldn’t have.”
Senku frowned. “That’s not an answer, Gen.”
Gen’s smile faded. “Then I would have handled it differently. I would have kept finding ways to make your life easier. This was just the most efficient idea I had.”
Senku pressed his fingertips together. “I can’t believe you married me like it was just a side-quest. I mean, you’ve been acting like we are a married couple for years and I just assumed that was your personality.”
“Come on, Senku-chan, it is my personality. But also a legal situation.”
Senku stared at the wall for a few seconds.
“...I need a drink.” He muttered.
Senku stood, made it about three steps, then stopped and turned back.
“...or, wait. Guess what? Give me one of those sugar-bombs you always drink. I could need the caffeine now.”
Gen lit up like he couldn’t believe his ears.
“Oh my god, you voluntarily want cola!? On my way!”
“Do not make this weird.”
Gen was already in the kitchen. When he came back, he handed Senku the can like it was a sacred artefact. Their fingers brushed for a second before Senku cracked it open and took a long sip.
He made a face.
“It still tastes awful.”
Gen beamed. “Awww, come on, it’s still better than your energy drinks.”
Senku took another sip anyway.
“Guess if it matters that much to you, I guess I’ll have to tolerate it.”
Gen’s smile softened.
“Careful.” He said. “That sounded almost like a vow.”
Senku huffed at that. “Almost?” He took another drink, grimaced again, then looked over at him.
“Alright. Then here it is.” He raised the can slightly. “I vow to consume this unholy, sticky nonsense once a year, on whatever day you say counts and pretend I don’t hate it. For you.”
Gen stared at him. A beat passed. Then he started laughing.
“God, Senku, you’re almost romantic when you’re suffering.”
“Also, you deserve a honeymoon.” He said suddenly. “A real one. Without fieldwork or experiments, just us spending time together. I’ll plan it and I’ll pay for everything.”
Gen looked up slowly, his expression caught somewhere between touched and amused.
“How generous.” He said. “But uhm, I hate to ruin the moment for you, love, but...”
He leaned forward, his chin on one hand.
“We’ve had a shared bank account for five years.”
Senku froze.
“We what.”
Gen grinned. “Mmhm. I used it to buy your microscope parts last winter. And all the presents for our friends. Also, most of the food in this house.”
“So you bought my birthday gifts with my own money?”
“Yeah well, technically you bought mine with it too.”
Senku just stared at him. “...you’re unbelievable.”
He was quiet for a second. Then he stood up and rested his forehead against Gen’s.
“I can’t believe I missed all this. But I’m glad I didn’t miss you. You’re the best husband I never meant to make.”
Gen smiled softly, then kissed him before Senku could overthink it.
“I’ve been yours for years, Senku-chan. You’re just finally catching up.”
“I love you. And, uh... please don’t ever make me accidentally sign a divorce form while I’m distracted.”
Gen slipped his hand into Senku’s and laced their fingers together. “Not a chance. You’re stuck with me for life. Legally and emotionally.”
He kissed his temple.
“Also I love you too.”