This is dumb beyond words. First, because it indulges in that whole idol purity bullshit as the biggest roadblock for Kirara. Oh my god, she had sex! Now she can't sing and dance anymore! Oh, wait. No. Turns out having sex doesn't rob you of your musical talent, it just makes you unpopular to weirdo purity-worshipping incel losers who can't cope with the idea that a person they like in a creepy parasocial way has a life outside of them.
Meanwhile he's going to be her manager, something the actual boss doesn't want and actively opposes, but somehow what's going to convince everyone to let him have the job is that he's setting conditions for his acceptance (which is silly considering you normally only have the leverage to set conditions when you are desired for the job, not when you're begging for it) two of which are a) I need to find out if I can even do this without getting fired from my real job and b) I need someone to teach me everything about doing this job that I just recklessly signed up for.
And then all of this is for the photos of him and Hebo, which he needs because he wants to marry her? That basically makes the photos irrelevant. Because 1) the photos get out and she would presumably stop being an idol because of the aforementioned purity bullshit or 2) the photos don't get out, but they would not be able to marry while she was an idol because of, again, the aforementioned idol purity bullshit. It's laid out directly in the second chapter that she would have to "graduate" before marrying.
They need to do this because it's the only way to maintain the drama and tension that the story requires outside of just focusing on the two of them getting to know each other, but it's so silly and artificial that it makes me not give a crap.
well not gonna argue completely against you so hear me out:
First that purity thing in Japan is a big thing like a big fucking thing, that depending on the fanbase can ruin someones career cause of the dumbest reasons.
Second the conditions he had are utter bullshit of a reason to hire him because of it, the point though is that it showed he was actually serious, showing his resolve to do this, which is probably what convinced the boss, aside from the boss just being a nice guy that seems to like kirara as well.
third and last thing: Yeah you right if that picture gets released she will be forcefully made to graduate and he could marry her faster... well if we ignore paparazzi and outraged fans that is. It is kinda a roundabout argument and I'd say there is a higher chance its just a plot hole but if we think about what would happen if that picture gets released then we can assume the following:
Massive outrage of her fans and increased activity of paparazzi around her, Which she could then slowly calm down after a couple of months and continue being an idol as usual under normal circumstances, but since she already planned to graduate she either needs to graduate a lot sooner and more abruptly or first calm her fans down and then graduate a year or so later.
If she graduates abruptly without having her fans calmed down enough then that will lead to a bunch of paparzzi trying to figure out who that guy is and what his relationship with the idol is. And thats gonna be a big pain in the ass, cause that means chances of a peacefull wedding and married life will be ruined for like half a year or smth and in the worst case some delusioned outraged fan might want to actually kill MC
So her safest way of dealing with that situation is break contact with MC and then continue as an idol or graduate and then keep it low for half a year or more till everything passes on and she can get together with MC again. Either way massive loss for the company and MC as someone who's picture was revealed might get a couple of problems