Let's see, I'll just go through my ComicRack library and see what I'd actually recommend...

For non-highschool yuri manga:

• How Do We Relationship, which is great and was something someone on here recommended to me in the first place. It's both sweet and soul crushing at times, and seems to finally be heading towards a conclusion after 122 chapters. Horny, but in a subdued and very queer way.
• Octave is very similar, but much shorter. Slightly horny, also in a queer way.
• Catch These Hands is a very short, very dumb story about a couple of former delinquents starting to date for contrived reasons, both of whom may actually be ace for how completely and utterly not horny at all this is.

Non-yuri manga:

• Dungeon Meshi starts off strong and has a lot of neat worldbuilding, but starts going downhill around volume 5 and jumps the shark somewhere around volume 10 or 11 in a way that completely ruins all the cool worldbuilding and earlier themes. Still recommend it, though. Not horny at all.
• Akumetsu is basically "what if Death Note was about Deadpool instead a whiny fascist dipshit and also it was specifically about that knockoff Deadpool killing expies of actual Japanese politicians over their corruption scandals?" and although I've only gotten through 5 of its 18 volumes so far it's pretty decent if politically incoherent. Not particularly horny, just some gross Eyes Wide Shut stuff in the beginning.
• ZOM 100: Bucket List of the Dead is amazing and manages to be a hopeful, class-conscious, pro-social zombie story about a couple of burnt out wage slaves setting out to do everything they'd never gotten to do because they were too busy working before it's too late, in the face of a zombie apocalypse. Somewhat horny.
• Booty Royale: Never Go Down Without a Fight is incredibly horny, problematic trash that's way better than it has any right to be and it actually manages to handle its subject matter somewhat appropriately. Still goes to very gross places and is fundamentally a story about exploitation, but it's also aware that what's happening is bad, actually and has its moral compass characters around to sort of offset that. Several times it stops the story dead to drily talk about actual, real world issues including railing against the Japanese government for its refugee policies being inhumane and racist and the abhorrent conditions in the refugee camps/detainment centers. I cannot in good conscience recommend it in general because of how gross and problematic it is, but it does deserve an honorable mention for how it actually has redeemable qualities and somehow handles its absurdly trashy subject material somewhat appropriately.