" I may or may not have imagined and reimagined them coming out/getting together/falling for each other countless times." Oooh, Lizzy, bless us with your headcanons/fics!!
I think Liz would have a more chilled-out “I like girls” sort of coming out, if she ever comes out. I think everyone would have just figured it out for themselves.
Leafa? I want her to be an emotional mess like I was. I want the days of “I can’t possibly like girls” “Maybe I like girls?” “But I’m straight!” until she finally realises that she’s a lesbian (these are my headcanons, please don’t attack me for them). I want her to tearfully cuddle into her brother’s chest (she’d obviously come out to him first) and whisper “I think I might like girls/might like Rika” (Second one maybe for fic purposes later? Also ignore my little notes here haha) while he pats her head and tells her it’s okay and it doesn’t change anything. Then telling her parents would be a little easier because she knows she has her brother’s approval and then telling her friends would be easier again.
In my opinion, they’d fall for each other (or start to realise they had feelings for each other) after that moment by the pool in Extra Edition. I also think this is where Sugu could be like “Wait that felt nice put your hands back wait sh*t no I’m not gay *existential crisis*”, and Rika more “Well… f*ck.” because that’s her friend’s sister.
Then they’d get to know each other a little more, spend time together away from the others (In ALO and the real world), and those feelings would slowly change from more “well she’s hot I GUESS” to “this girl’s actually really cute and sweet and funny and I think we get along great and I really wanna spend more time with her!”.
Then they’d both sort of have this moment where they realise “I’m in love” and it could sorta be this big realization.
Rika would make the first move, no doubt. Suguha would be way too shy and nervous. She’d probably do it really casually when they’re hanging out, maybe just reach over and hold her hand to see how she reacts and then if she seems okay with it say something like “I have feelings for you, and I was wondering if you wanted to see a movie together/other generic date activity”. Of course, Sugu would be a blushing mess but manage to say she felt the same and then they’d go on a few dates.
I think they’d officially get together as girlfriends when Rika walks Sugu home one night, kisses her cheek at the door and does the whole cheesy teen romance movie thing. Like, “Suguha, will you be my girlfriend?” quickly followed by Suguha’s incomprehensible gay squealing (AKA how I reacted when my gf asked me out officially).
Then they’d be a normal couple, and they’d totally have movie nights and build blanket forts and snuggle and stay up late texting and trading stories and telling each other all the dumb stuff Kirito does/has done. They’d be super cute and relaxed and just a chill but committed couple.
Anyway, I got carried away, I hope you still made it through the long post! I could talk about headcanons for these two for HOURS.