"You mean you used me as a fluffer?"* Technically it translates to "appetizer", though considering he's a vampire, the meaning is almost exactly the same. Said as Kojou embraces Yukina briefly to get aroused enough to take Astarte's blood. Girl doesn't know what a golf club is, does know what a fluffer is. What do they teach at Lion King Academy anyway?
While Yukina is taking a shower, Kojou innocently tries to go shopping outside. Assuming he is trying to escape her vigilance, Yukina leaves the shower in a hurry and barely take time to put back her clothes… offering to Kojou the sight of her half-dressed and still wet self. Also, her wet blouse makes it obvious she isn't wearing a bra. Kojou is understandably shocked, but she stays him with a stern look on her face.
Kojou reading Yukina's measurements on the party dress sent to her by the Lion King:
Boy: Hey, keep still. Come on, quit struggling. Nagisa: No! Don't squeeze so much! Boy: Sorry, I'm not used to this… Nagisa: Th-That tickles! Boy: If you're too loud, someone mighthear us! Nagisa: I know, but getting licked like this…ah, that hurts! Kojou:[Busts through the door] Break it up, you two!
Yukina: You're actually quite the sisco-worrier, aren't you? It's a little disturbing.
Yukina and airplanes.
Kojou: You okay, Himeragi? Your face is the color of paper. Yukina:Of course I'm okay! No problem at all! Kojou: Wait, are you scared of airplanes? Yukina: Of course not! I'm a Sword Shaman of the Lion King Organization! [The plane lifts off.] Yukina:AAAAAAAHHHHHHHHH!!!
Sayaka and Asagi bicker over Kojou while they try to find where he and Yukina have been sent off to by Possession Mask. Yaze has to step in to get them back on track. He does so by making them aware of the fact that Kujou and Yukina are alone on a deserted island, possibly heading towards a "Blue Something-or-Another moment". Sayaka and Asagi quickly declare a truce.
After Kojou is almost killed by Kanon, Yukina gives him her blood to help him heal and possibly unlock another familiar. She ends up lying flat on her back, half-naked and unconscious from blood loss, just as Kojou wakes up on top of her.
Kojou:What the hell?!
La Folia kisses Kojou right on the lips, right in front of Yukina and Asagi. Then she just flashes them both a cheeky grin.
Astarte: Confirmed intrusion by the Fourth Progenitor.
While Kanon and Astarte take it with pretty good grace, Kojou has a good deal of trouble getting Yukina to focus on the main issue afterwards.
When La Folia finds out what Yuuma has done with Kojou's body, namely swapped his with hers, she shakes her head and says "This is quite a problem, Sayaka. I can't produce an heir with him like this."
Yukina, pressed for time, sums up the whole mess succinctly: "Some things happened, and he's a girl now".
Kojou's mom claims to be a tactile psychometric whose powers are activated by fondling the breasts of cute girls.
Yukina: You truly are your mother's son.
Later we discover that apparently she wasn't actually joking.
Just when you thought Asagi was going to inquire about Kojou's true identity during the bath scene on board of Vatler's ship, she comes out with this gem:
Episode 23: Kojou and Yukina's time-travelling daughter acts exactly like you might expect from that description.
The real kicker is when said character meets Yaze: "Well, you're much thinner. And your hair's so thick…"
Then Natsuki shows up and gropes her.
Vatler, of all people, awkwardly looking away and rubbing the back of his head when Kojou sucked Yukina's blood in public while the battle with the time-traveling dragon was momentarily on hold.
Kojou and Yukina's daughter's expression as she watches the same thing.
It turns out that Yukina mistook a reminder for a regular medical exam as an order to return to the Lion King Organization.
Kojou and Yukina finally figure out just who is the time-traveling girl.
Yukina: That's my uniform. She took it when she knocked me unconscious. Kojou: She seriously looked a lot like you, though. I almost thought you could have been mother and daughter. Come to think of it, didn't she call you Mom? Yukina: But she was a vampire, right? Kojou: Huh? [Awkward silence.] Kojou: Nah, couldn't be… Yukina: Y-You're right.
In the "Kingdom of Valkyria" OVA, King Lucas Rihavein of Aldegyr was already in Papa Wolf mode due to his daughter's romantic interest in the Fourth Progenitor. He becomes even more upset when he finds out that Kanon (his wife's half-sister) was the same, and angrily asks Kojou "just how many girls have [he] sunk [his] teeth into?" Lucas meant it metaphorically, but Yukina, Sayaka and Astarte self-consciously cover the side of their necks with their hand. The implication is enough that the king pulls out a literal axe to grind against Kojou.