Hidden Gem/Non-Mainstream Anime Suggestions?

So I've found myself looking for a new series to watch and honestly, I'm having a hard time doing so, Thus I'm turning to the people of MaiOtaku to help me. Anyways, Basically I'm looking for things not so mainstream or Hidden Gem's I suppose. I don't want to watch anything making the rounds currently or any over popular shonen. I want something that could potentially be considered a fun unexpected experience. So if you have any anime like that stored in your head feel free to share said information here I'd appreciate it.

Problem children are coming from another world, arent they? Only 10 episodes but its good and will get you to want to read the manga Oh and Aesthetica of a Rogue Hero. Super ecchi but super funny too. Left on a cliff hanger tho and wont get a second season like the one above but also super good and will also get you to want to read it to see what happens And my fave which not many people have seen, Phantom requiem for the Phantom. If you give it a watch u'll see why

idk about anime but i have tons of manga i guess osomatsu-san its big in japan but i havent really seen it talked about in the western anime community its hella funny https://68.media.tumblr.com/e3ae1d2f8be396dd6694991cba278939/tumblr_o7caajfRq31vude0ho1_500.gif