tl;dr version: Nomoto = Episode 2 / Kasuga = Episode 4

While Nomoto really started since the beginning, it was just kinda emotions raging in general because OMG there's someone who loves to eat a lot of food and she wants to make a lot of food!

But the way Kasuga reached out to her to take care of her when her period started was that "sparkling" moment for her. She didn't even MENTION anything but Kasuga had a feeling something was wrong and reached out to her. She got her supplies. She cooked her comfort food...and she gave her some soothing talk about self-care and to not push oneself and compare with others.

Anyway, see, that is the look of someone finally struck with the Arrow of Love~

As for Kasuga...ah, stoic Kasuga... At first, I'm pretty sure she just wanted to invite Nomoto out to the market because they just haven't hung out recently and wanted to make up for it. But if you watch, there's signs of something sparkling as she watches Nomoto get all giddy~

She didn't want that day to end. She saw that pumpkin and thought of something to keep them hanging out longer, and them talking about these things they would've never done before meeting each other? Nomoto we know is already stricken, and then Kasuga admitting she's blushing. It's definitely more subtle with Kasuga, but you can just TELL this was the moment. This was the moment she wanted a connection.

Romance wasn't exactly in her mind just yet, but there was definitely this vibe of "I want to be close to her." And it's really heart-warming to see.

...anyway, ending on a silly note: Okay, ladies, I answered your S2 Ep20 question way more specifically than you two did. Do I win a big ol' homemade meal made by you two or something?