'‘I like you more than a friend’'

I've been living in Jpan for a year and have a basic command of the language but still can't work out more subtle or sensitive sentences. I'm friends with someone that i'd like to have a relationship with, I dont want to say something as strong as i love you, so how can isay something along the lines of i like ou more than a friend, or i want to be more than just friends?

you can start with
"Tsukiatte kuremasuka? (Can we go steady?)"
or
"(Kondo futari de nomini ikou yo) Let's go out for a drink sometime, just the two of us."
depending on how serious or how far you want to go.