Who should i put as love interest?

I'm a little hesitant about who shuold be, so i decide to ask you guys your opinion.

Just don't ask for a harem, i really going to break my brain doing that. 

I'm gonna try to make this story following the canon (so yeah you can expect volume 1 to 5)

Back to the topic, i already have an idea about the love interest, but then again i'm hesitant about it. So what do you think guys?