Something something Tobirama being the most-least parasocial fan to ever fan. He becomes obsessed with performer Madara (music, stage and film) and runs a meticulous fan account online documenting projects, press releases and endless photographs and videos. He has intense, extremely detailed, practically novel-length sexual fantasies about this man and this man alone. He pays an artist to realistically recreate a low-res, darkly lit screencap of Madara undressing to a fundoshi in a samurai film and nails it to the wall directly opposite his bed so he can go to sleep every night to the pure art that is Uchiha Madara's muscular tits, hairy belly , and (likely padded) bulge.
Hashirama gets tickets to Madara's concert because he's literally the only musician Tobirama not only listens to but also owns the physical songs of and Tobirama is mildly interested. They have a good time drinking cheap beer (something Tobirama doesn't usually do) and dancing (also something Tobirama doesn't usually do).
When Tobirama somehow wins a random selection to join the meet-and-greet line, he declines. The assistant is bemused and tries to reassure him that it is all free, including the merch. Tobirama perks up at this and joins the queue. When it comes to his turn to "meet and greet", he walks up to the table and ignores Madara for a full five minutes while he carefully browses the merch on display for something he doesn't already own. Finally, he selects a special edition DVD. Madara uncaps his marker to sign it and Tobirama marches away without a word.
Madara, who utterly loathes meet and greets on the best of days, is downright baffled.
Hashirama is also baffled, but slightly less so. He warmly apologises for his brother's unsociable behaviour and assures Madara that they had absolutely loved the concert.
"Is your brother differently abled...?" Madara asks politely.
"My brother is disabled and also an asshole," Hashirama says brightly. "Would you sign this CD? My youngest brother is also a big fan of yours! He couldn't be here tonight because he's a nurse."
"Aa, here you go. Please tell him that he has made an extraordinary sacrifice for his country."
Mostly sarcastic, partly genuine. Tobirama rolls his eyes and studiously ignores Hashirama bantering back and forth with an arguably huge celebrity.
Finally they head out. Hashirama is clutching a sheet of paper with a big smile.
"Look here! Uchiha told me he'd upgrade my tickets next time for free so I can bring Itama to meet him. What a swell guy."
"He's just selling you shit, Elder Brother."
"Oh, hush. I thought you liked Uchiha!"
"I like his music and I like his acting." And his body, but that is none of Hashirama's business. "He's arrogant, pretentious and far too big for his average-sized boots."
"Ehh? How big are his feet?"
"And how do you know that?" Hashirama asks patiently.
Tobirama pretends to find his DVD fascinating.