Jiro Matsumoto: everything this guy does.
I second this one. Jigoku no Alice is fantastic, and Freesia is sublime. I dread the day when the algorithm feeds this guy's works to the zoomers and they gentrify it, like they did with Berserk or Cormac McCarthy's stuff.
I'm surprised you didn't recomend Eden:It's a Wonderful World, since it's your avatar. Unless that's not obscure anymore. Maybe the algorithm got to it.
My recommendations (other than Freesia):
BioMeat: Nectar: Japan bioengineers an organism that solves all their problems: tardigrades that feed on garbage, and humans can eat their meat. One day, they breach containment and spread across Japan, eating anything... and anyone they encounter. A group of kids gets caught in the wake of the all-consuming monsters, and they must escape! It's a ton of fun.
Ciguatera: It's a dark coming-of-age story like Goodnight Punpun. Unlike Punpun, it has happy moments to create contrast from the depressing parts. It manages to capture some great bittersweet moments, feelings of genuine child-like joy, and some gut-wrenching darkness.
I also recommend Wanitokakegegisu from the same author.
Fraction: WARNING: This is by Shintaro Kago, a guro artist. This one is gory, but it's a mind-bending work of art. It's about a mysterious string of murders where people get cut in half. Simultaneously, there's a meta story about the actual author, Shintaro Kago himself, writing the serial killer story and explaining some technical aspects of manga writing, which are some cool insights. I can't give more away without spoiling, but the twists are amazing and flip the story around completely several times and it devolves into a deranged mess that will leave you howling.
Anime: Marriage of God and Soul Godannar. This is a litmus test. If you don't like Godannar, you don't like anime. You're a normie and should be gatekept. It's the anti-Evangelion. It says "No. Giant robots are amazing, and you're a faggot for suggesting otherwise. Now look at these titties."