WARNING: The following contains spoilers for Episode 9 of Girlfriend, Girlfriend, "The Tsun's Dere Gets Outed" now streaming on Crunchyroll.
Nagisa and Saki deal with a lot in Girlfriend, Girlfriend, but Episode 9 puts them through their biggest challenge yet. Over the previous few episodes, Naoya and his girlfriends were dealing with Rika, a famous MeTuber who is vying for Naoya's attention. In Episode 9, this situation comes to a head. Rika decides to properly tell Naoya how she feels about him, meaning Nagisa and Saki have to face the possibility that Naoya could return her feelings.
Even though the thought that Naoya may want to include Rika in his dream harem is devastating, what actually happens is far worse. Frustrated, embarrassed and gaining no ground with Naoya, Rika decides to just go for it, kissing Naoya in front of Nagisa and Saki.
Much to everyone's surprise, including Naoya's, Rika plants a big old kiss right on him in the middle of the school day. Naoya had made it clear that he cannot return her feelings due to his dedication to Nagisa and Saki, but Rika wasn't okay with that answer, so she dedicates herself to winning Naoya over, no matter what it takes. Embarrassed as she is, she therefore kisses him with full force, hoping to leave him wanting more.
Unfortunately, she performs this act in front of Nagisa and Saki. Of course, they take it personally -- neither of them has kissed Naoya yet, and Rika has stolen Naoya's own first kiss away from both of them. Saki is especially hurt. Naoya has liked her since childhood, and now that she has finally agreed to go out with him, she was hoping to share a momentous first kiss. That opportunity is now gone forever.
Nagisa is pretty hurt by Rika's kiss as well. Although she knows that Saki is the original girlfriend, she had hopes that she could win over Naoya's heart and his first kiss as well. These are dashed by Rika's bold actions. Both her and Saki struggle to cope with it, and will likely bring it up in episodes to come.
Naoya also feels terrible about the situation. He is completely shocked by Rika's kiss and understands why it hurts his girlfriends so badly. He tries to make it up to them but realizes it's going to take time. Rika's actions have thrown a wrench into Naoya's harem, and it will take a lot of effort to keep it from completely falling apart.
