
Sorry, but it is rape. By using emotional manipulation he put pressure on Sungho to do sexual acts he clearly doesn't want to do, it's called sexual coercion.
Coercion is the use of emotional manipulation to persuade someone to something they may not want to do – like being sexual or performing certain sexual acts. Examples of some coercive statements include: “If you love me you would have sex with me .”, “If you don’t have sex with me I will find someone who will.”, and “I’m not sure I can be with someone who doesn’t want to have sex with me.” Being coerced into having sex or performing sexual acts is not consenting to having sex and is considered rape/sexual assault.
So if Dohyum is implying that “If you don’t have sex with me I will find someone who will” it is “coercion,” and thus means that any resulting sex is not consensual. This means that getting sex that way is “rape and/or sexual assault” (because it’s “coerced sexual contact”).

That's the confusion, though, isn't it? I may have to reread that chapter that had that flash back, but I don't think there was any manipulation like you stated, which is why I'm on the fence. There's manipulation and then there's pressure. A boy won't be arrested for emotionally manipulating his girlfriend into having sex with him with the coercive statements you gave as an example, if they were, every boy would be in prison. A thin line, I know.
Don't get me wrong, I know exactly what you are talking about, and I agree with you to a certain point. To a certain point, because we don't know if Dohyum had made any of those kinds of statements, right? Assuming is death ;p We don't know, why is why I love this story (I could do without the rape, though) We know that Sungho didn't want to do it so it was coercive on his part, but we don't know if Dohyum knew he was forcing Sungho into a sexual act or if he thought Sungho was willing after telling him that he wanted after saying he didn't.
I think I confusing myself LOL. You make my brain think. I love you (▰˘◡˘▰)

I also think it's not rape. The problem is Sunghos extreme obsession since his school days.

It was not rape.
We have never seen Dohyun verbally or physically forced Sungho who did his mental gymnastic and made the decision.
Sungho never voiced his opinions that he didn't like doing it to Dohyun. In chapter 33, Dohyun realized that Sungho didn't like the sex back then and told Sungho that he should have spoken, which means he wasn't aware of Sungho's feelings. Dohyun did it because he liked Sungho and thought that Sungho enjoyed sex. That was insensitive on his part but he did not manipulate Sungho.
Translation was wrong:
Here, Sungho said, "Wait a minute. Not like this. I want to spend time doing other things."
http://www.mangago.zone/read-manga/warehouse/uu/warehouse-chapter-28/6/
Dohyun said here, "Oh, did you not like it? You wanted me to pay you? You should have told me, you fucker."
http://www.mangago.zone/read-manga/warehouse/uu/warehouse-chapter-33/9/
http://www.mangago.zone/read-manga/warehouse/uu/warehouse-chapter-33/10/

Rather than rape, it's probably better to categorize it as non-consensual sex.
As stated in the Five Vices of Consent, this might be what you call the "undue influence" where a party's volition is controlled and they're unable to resist it. It is obviously shown that Sungho was obligated to accept everything Do Hyun asked because he loved him and didn't want to be shunned by him for refusing his favors.

Lmao what? First, anyone can be obligated to do things out of love. But I'm not sure if this is love in the first place. Second, this situation is not applicable to Sungho's kidnapping. Maybe you should do some reading about "Five vices of Consent", the "undue influence". Clearly Sungho was not very happy with the sexual things he did with Do Hyun, he had wanted to do normal things like normal friends would do. But he couldn't refuse him didn't he?

No, obligation means you have no choices because you're bound to do it. If you do something out of love, that's by choice. It's not obligation. What do you mean Sungho could not refuse? He could refuse. He could say "no" any time. No one threatened him either verbally or physically. He wanted something (Dohyun's being around) and he willingly had sex for that. It's called an exchange.

https://www.batasnatin.com/law-library/civil-law/obligations-and-contracts/2344-consent-in-obligations-and-contracts.html
English cannot win against written laws, sweetheart. Your understanding about the word is only the tip of iceberg.

I was not attacking the website. I was pointing out the lack of credibility from the site that you linked to. When you quote someone, you need to research whether the source is reliable or not and a law firm from Philippines is not. Since you start resorting to insults instead of reasoning like adults and I'm not willing to stoop to your level, this will be my last message in this thread.
Poor Dohyum. Everyone in high school are assholes, but Doh didn't rape Sungho then. Pressured him into sex maybe, but it wasn't rape. Sungho had the option of saying no, but didn't because he had feelings for Dohyum...but resents the sexual part of of Dohyum's 'like'. What Sungho really needs is therapy, like, major friggin therapy.
Sungho is going bat-shit crazy now. I mean, he was already nuts, but I think he's completely fallen off the deep end now. He almost killed Doh-boy.
Thank you for translating this so much! This has been the best story (because it actually has a plot-line, and isn't just a 'smut-line').