I can't say the best but these are what came to mind first.
Love, Chunibyo & Other Delusions. A slice of life story about a few different pairings getting together. But mostly about a pair becoming more mature and dealing with trauma.
Chobits, a robot falls in love with a man, exploring the ethical and social issues with that.
https://anilist.co/anime/14741/Chuunibyou-demo-Koi-ga-Shitai/
Among many options available the fastest solution would be to place your hands into the antimatter field.