Both look male to me in the intro panel. They just have anime hair and faces.
Generally the clothes are the biggest giveaway if the face/hair don't make it obvious, both are in stereotypical male clothing here with no characteristics that imply otherwise.
What do you think she was doing? He needs to either step back and take the role of just a friend or move forward and be a romantic partner. He can't exist in between those two when Emi wants him romantically, that only ends with her being hurt. Sending him home after making him answer that...
Makiba is the only manga character who actually just follows his feelings and I love that it's been consistent from the very start. Bro just went for it