Interval Zero talks about Kadokura from Junketsu Drop, but has nothing to do with the original. I was originally happy this manga had some buildup before the actual romace/ero parts but while I was reading I was just unimpressed with the whole setup and conclusion. In my opinion, Kadokura seems like a completely different person from what we've seen of him before, his family situation is a total asspull, the whole romance made zero sense.
The plot is a shitfest especially towards the end. The whole load of crap with his former senpai was useless. Can I talk about how much I hated the ending? I
hate the message the manga gives: love doesn't solve everything. There was no progress made, MC is still a fucking servant and I completely don't believe MC and Kima love each other. There's no love, only manipulation... This manga was an absolute disappointment.