Kuzo no Honkai

If you think this is a normal romance anime please be informed that this anime contain 18+ scenes. So you will find mature and smut and can be label as a hentai. Its NTR as well. lol
(NRT can be defined as someone's girl/guy being stolen. It can be rape or not even have holding hands, as long as he/she falls in love with the other person.)

The anime itself is not for the weak heart but if ur strong enough then you can give a try for the anime (currently airing) or read the manga since its almost finish.