Mysterious Girlfriend X

Tsubaki and Mikoto have been “going out” for a month. Tsubaki is confused about his role of boyfriend and looks to his friends for help. Can their relationship continue beyond drool?

Out of the blue, Oka has taken an interest in Urabe. When she asks Urabe to be her friend, Urabe tells her she doesn’t need friends. But that feeling might change once the two girls share a drink.

After having a conversation with Oka about first names, Tsubaki wants to call Urabe by hers. While waiting for Urabe, the girl from the picture he once carried in his wallet stops him to talk, and surprises him with a question.

Akira has a dream where he got to squeeze Mikotos breast and cant get the sensation out of his head. Taking a stroll, he decides to go in the direction Mikoto usually takes after school and comes up to an apartment block, which turns out to be where Mikoto lives. Mikoto invites Akira into her apartment for tea, where his imagination starts to get the better of him. After catching Mikoto as she trips after being spooked by some lightning, Akira almost reaches for her breast but Mikoto stops him. After getting Akira to tell her about his dream, she feeds him some drool whilst grabbing her own breast, giving him a stronger sense of the feeling. She then allows Akira the opportunity to touch them for himself, which causes Akira to become more aggressive and tease her ears until she notices Mikoto is crying and runs off. The next day, after Mikoto gets some advice from Ayuko about the new experiences she is feeling, Akira asks Mikoto to slap him as a way of apology. Afterwards, Mikoto explains the feeling she gets when her ear is touched before taking on Akiras bruise herself.

Akira runs into Aika who, having just been dumped by her boyfriend, reveals how she knew of Akiras feelings for her when he lies about not having a girlfriend. Aika gives Akira the opportunity to try some of her drool, but he backs out realising it could damage his bond with Mikoto, bringing to light that he does have a girlfriend. The next day, Aika decides to approach Mikoto, inviting her to her schools culture festival on Sunday with the news that Akira might be there. Later that night, Aika calls out Akira with a fake wound on her face, manipulating Akira into coming to the festival with her and pretending to be her boyfriend. Akira tries to come up with an alibi in front of Mikoto, but she soon learns the truth from Ayuko. As Akira goes to the festival on Sunday, Aika shows up wearing her old middle school uniform.

As Akira is a little bashful around Mikoto, having seen her naked and all, she requests to try his drool, her experience how flustered he is. The next day, when Mikoto uses her scissors against Akira for attempting to hug her, she is shocked when she sees she had cut his forehead a little. As Mikoto takes Akira to her home to get his injury treated, she finds her scissors have become less accurate, which she believes to be caused by a strange dream she had after trying Akiras drool. As Mikoto gives Akira more of her drool, he starts picturing Mikoto naked and ends up banging his head whilst trying to avoid hugging Mikoto on impulse. After hearing his reasoning, Mikoto decides to hug Akira of her own accord, which in turn restores her scissor technique. The next day, as one of his classmates offers to replace Akiras gauze, Akira opts to keep it as it was the gauze Mikoto gave him. Later that day, Mikoto once again initiates a hug.