'She didn't need to clarify it though. If there was nothing there, a simpe "I love you too" would add up more. Like, you don't clarify the "as a friend" or "as a family member" etc, when you say I love you to your friends and family. Also the way her expression was drawn was weird.'
In the situation, I don't think "as a friend" means anything about Harumin. Given that Yuzu had just come out as being into girls, or at least one girl, and Harumin herself being a girl, it could be simply clarification, not self-denial.
I remember hoping for Harumin/Yuzu myself, but I think I based that on her facial expression, not words like that.