These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Isagi Houjou asks Ran to dance with him, as he would rather dance with "beautiful" Ran than "strange girls," comments that Ran should wear a dress, calls her "Ran-chan," and steals a kiss from her. Subverted as Ran is a girl and Houjou knows this because he's old friends with Rei, but everyone who doesn't know that assumes that Houjou is interested in a guy until Sei lies that Houjou's antics were a "performance" to liven up the dance.
After learning about Ran's true gender, Souda admits that he did notice that her facial expressions were pretty at times and that it made sense that she was a girl. He even adds that there were times he thought he was turning "gay" because of her.
At one point, Ibara even teases Sei, saying that she must sure love her "sir knight," and Sei agrees with a straight face, which later causes Ibara to wonder if Sei meant something different with Ran and wonders if he's thinking about it too much.