In Chapter 54.5, Momoka is musing to herself while onstage about Urabe and Tsubaki's "Bond of Drool". Thinking about what she saw between them when Urabe was performing, she licks her finger and strikes the same pose that made Tsubaki's nose start to bleed at the concert. After wondering if the boy that she would one day have a bond with could be on the other side of the camera watching her right then, the scene shifts to a boy sitting by himself watching her on the TV, and his nose starts to bleed. "I hope...these feelings...reach him!" "Ah...Huh?...Why is my nose bleeding?" You never clearly see his face, only enough to know that it definitely isn't Tsubaki.
Urabe's apology and general freak out when she nicked Tsubaki with her scissors, if only because unlike many, many Tsundere hissy fits throughout the anime genre, she not only felt bad, but apologised to his face and tried to fix him up as much as she could.
Tsubaki coming over to Urabe's house when she's ill to prepare special food for her. For a romance manga running on weirdness and fetish appeal, this mundane act comes across as one of its more intimate, touching moments. Also, how often does one see guys doting over girls in media compared to the other way around? It goes further: Tsubaki can't stay overnight but he drapes his shirt over her while she's sleeping, and she dreams he's at her side, his hand on her head. The next morningUrabe is wearing nothing but his shirt - and her illness is gone.
Tsubaki and Urabe paying their respects at the grave of Tsubaki's mother. Urabe dresses up for the occasion as if she were presenting herself to Tsubaki's family as his girlfriend, and acts as much.
The same theme appears when Urabe runs into Tsubaki's older sister Youko. Urabe introduces herself as his classmate and Youko recognizes her from the times she's been to their house. They end up going for coffee. When they part ways, Youko tells Urabe to "take care of Akira [as a friend]". Urabe is in fiancé-meeting-the-parents mode, as she introduces herself formally and says "I hope we get along well from now on." Later, Urabe tells Tsubaki she'd like Youko to be her sister in the future.
In episode 8 Tsubaki requests that Urabe slap him for accidentally making her cry the previous day. She does, and then promptly takes some of his saliva to share the injury. For a girl that has occasionally points a pair of scissors at her boyfriend she can be very caring.
Chapter 68 of the manga, both in the story and the movie within the story. Tsubaki has been freaking out because Urabe's drool is beginning to taste flavorless instead of its usual sweet taste and he's worried about their relationship. Meanwhile, in the movie his club has been making it's revealed that the character Urabe is playing is really a robot looking after him who also has flavorless drool. For the final scene of the movie Tsubaki tastes her drool and is finally able to tearfully say:
Tsubaki: I don't really get it, but it tastes... sweet.
Followed by the most heartwarming smile we've ever seen Urabe make. An absolute Tearjerker.
Chapter 74, where Tsubaki is spending Christmas with his family. They have a miniature Christmas tree that his Missing Mom had bought for them years ago, but now it's fickle in when it chooses to function. Having told Urabe about the tree and hearing her desire to see it, he takes it to her, and she—wearing a cute Santa outfit that her father bought her and that she wanted to show Tsubaki—gets it to work...and in doing so, gives him one of her rare smiles.
It's just an old Christmas tree my mother bought...but because it's this fickle old tree, I get the feeling that being able to see Urabe's smile tonight may have been a gift from my mother in heaven.