Wow Judith, i was thinking about your phrase...if you are going to say that first consider the following:
if is a male friend and you say that you might scare him...(believe me that situation had happened to me)...
watashi mo anata ga suki desu (i like you too)
watashi mo aishiteru (i love you too) this is very strong for saying to a friend.
thanks my friend: arigatou watashi no tomodachi (but this is very literal), so don´t pay attention to me and wait for the natives opinion.