Well, this other poster got a couple things wrong. Given that as a ghost he continually rapes Kousuke, but as a living human being he apparently won't, it would seem more likely that Yuuji WOULD go out with 'living' Kousuke, given how he already knows that he is a high school student (so that wouldn't have made ANY difference in his decision, I'm sure). And it's not sexy sex, it's rape. And constantly being sick at work or getting caught by his co-workers in a 'compromising position' could lead to Yuuji being fired from his job. What money does a high school student think he can make that would be able to support the two of them? And I don't feel ANY love from ghost Kousuke.
The thing is that ghost kousuke thought it was all a dream at first, so he thought he could do whatever he wanted. So when Yuuji finally confronted the not ghost kousuke, he realized it affected Yuuji irl (idk I think he should realize that he's a ghost irl but that's what the raw said anyway.) So he kinda didn't wanna go out irl.
All in all they're happy together in the end. This is not a heavily dramatic manga so of course, they wouldn't have problem such as being found out by Yuuji coworker nor will Yuuji get fired.
PS the not ghost Kou-kun is also pretty reasonable and thoughtful too.
Someone in the older comments said that they kind of read the raws, and came up with this. It kind of makes sense too. I don't know, because I can't read the raws. What do you guys think?
Spoilers...
"From what I could read from the raws...
So on the night that Hatsuki (colleague) mentioned, Yuuji's (uke) unrequited love was ended by Hatsuki's marriage engagement and was dead drunk. He ran into Kousuke (seme), who was in the middle of a fight and having a bad day (girlfriend problems), and he helped him out. Then Yuuji went to a bar and cried all over Kousuke, and that was when Kousuke's heart when 'doki' 'doki'.
But Hatsuki came and took away Yuuji and Kousuke was left desolate. So, one night, Kousuke fell asleep and found that he could float around in ghost form. So he found Yuuji and well... Ch. 1-4 happened.
The not-ghost!Kousuke feels like Yuuji and him shouldn't be together, for certain reasons (they don't REALLY know each other, not really consented first time, etc...), and so he tries to walk away from it. Yuuji straightens him out and they have sexy sex. Not-ghost!Kousuke then falls asleep, and Yuuji once again encounters ghost!Kousuke. Ya'll know what happens next... yuuuupppp. Sexy sex. Looks like Yuuji ain't going to get much sleep anymore.
Kousuke can't dp Yuuji's ass because the way Kousuke switches, is through sleeping. Ghost!Kousuke only comes out when not-ghost!Kousuke is sleeping. I also think ghost!Kousuke had office sex with Yuuji during the day, by sleeping at school (he's a high-school student)."