I really like you!
The Art Of Kokuhaku in Japan is also sometimes called the “Third date love confession.” By the third date, you say how serious you are in the relationship. It’s called a love confession but in America we would understand it to be closer to a “really like you” confession.
In any case, don’t do it like I do — blurt it out really loud halfway through the first date, “I really like you!” as the restaurant quiets suddenly and everyone turns their head toward your table.