So I've watched My Holo Love, My First First Love and Love Alarm so far, but somehow I can't find any more that are in German.
I still know sweet home.
Thank you.
I know the following German-synchronized series on Netflix (and you already know some of them):
Romantic: "My very first love", "Love Alarm", "My Holo Love", My First First Love
More like horror / thriller: Sweet Home, Extracurricular, Kingdom. Alice in Borderland (I think)
Then there are School Nurse Files, which somehow doesn't really fit into any category.
What you can do is use and search through Flixable (https://de.flixable.com/) filters. Audio can be set to German there. I mean, Asia series per se can't be searched, but "international series". Then you can sort and scroll through by rating.
Otherwise you can sometimes find series by Googling if you are looking for Dramatitel + Ger Dub / Ger Sub. Then you have to decide for yourself whether you want to trust the provider or not. But I can't give you a lot of hope, dubbing is apparently simply not worth it with the few German-speaking people who don't speak English. And even English dubbing is the exception…
Most of them are available with German subtitles at most. If that is also an option for you, then you can also look at Viki, there's then a lot more, legally and often for free (but then with advertising)