I know this is a cliche trope but hear me out ... bodyguard/idol nanago au ...
Gojo is the top idol of Jujutsu Entertainment, and Yaga, the CEO of JJ Ent hires Nanami as a bodyguard/manager to Gojo, and naturally Gojo falls in love with Nanami because he's unbelievably hot, has a good body, smells nice, BUT
Nanami has seemingly zero (0) interest in Gojo. Gojo invites him to drink with him numerous times, and gets rejected. When Gojo attempts to be flirty and gives Nanami an Inkigayo sandwich ( *idols put their numbers in the sandwiches ( like a slip of paper in the sandwich ) and pass them to romantic interests ) Nanami just takes the piece of paper out, and gives the sandwich to Yuuji ( one of the younger trainees in JJ Ent ). After Gojo does rehearsals for his songs, especially the love songs, he approaches Nanami and is super flirty, like " Hey ~~ Na~na~mi, how did you think I sang just now ? Good, wasn't it ? " but instead of blushing or giving any indication of interest, Nanami just gives him a look and hands him a bottle of water and tells him to drink up and Shoko ( Gojo's fellow idol friend and long time colleague ) + Getou ( Gojo's long time actor friend ) + Yaga finds it hilarious because it's the first time that Gojo's been humbled so hard, and Gojo's confused and embarassed as well because he knows he's attractive, so why is Nanami not reciprocating ??
Anyway angst time for the plot : so I think Gojo would be a perfectionist despite his confidence, so I imagine him practicing so hard until he falls sick, and even so, he still pushes on until like until 4 am in the morning, until Nanami bursts in with a plastic bag of painkillers and water and asks him to take a rest, and he starts cleaning up and tells Gojo to go get changed and put his shoes on because he's going home to rest, and because Gojo already doesn't feel well and he's so vulnerable, he just starts crying and Nanami's stunned, of course, but he just hugs Gojo and soothes him, until Gojo tires himself out, and he ends up driving Gojo back to his apartment, tucking him into bed, and staying up to make sure Gojo's fever's going down ...
And I think Gojo would be confused because the next morning when he wakes up, Nanami's still there and he's made porridge for Gojo and he's being very tender and sweet and it's very unlike him !!! But anyway turns out Nanami wasn't rejecting Gojo because he wasn't interested, he did like Gojo back but just thought that what he did was for publicity ( to get more people to talk about him ) and he didn't want to get his hopes up until the younger trainees ( Megumi and Yuuji ) confronted him about it and they told him everything about Gojo's feelings towards him ... and adding on, imagine if Nanami's insecure about his looks and didn't believe that Gojo actually liked him and thought it was part of his " persona " the company made him put on.
I'd like to imagine Gojo being really motivated afterwards, like he wins the kpop countdown stage and when he gets backstage, Nanami grabs him and just gives him a hug and a kiss and Gojo's completely red !!!! Gojo can't even be angry when Nanami tells him Megumi and Yuuji and basically all the trainees told him that he had a crush on him ( Nanami ) and then they live happily together, Gojo as an idol -- until he retires, and Nanami as his manager/bodyguard, his boyfriend, and his number 1 supporter !!! <33
As a bonus imagine Gojo at one point asking Nanami to be one of the backup dancers for one of his more sensual songs and in one part of the dance, Nanami has to grab(?) Gojo's face and stare really intensely into his eyes and most of the dance requires a lot of touching on Nanami's part and after that stage, all of Gojo's fans, very predictably immediately start talking about the " sexy backup dancer " and start asking Gojo for his @ and they're like " how to be Gojo :") can the backup dancer hold me like this too " and Gojo sulks for a whole day after that much to Nanami's amusement, because " how dare they flirt with my boyfriend ... " ( When he complains to Megumi, Megumi reminds him he was the one who asked Nanami to be his backup dancer so technically it's his fault )
