Urd makes a love seed for Belldandy to help her with her relationship, but Skuld secretly interferes and makes her act very aggressively toward Keiichi.
Summary
Keiichi shapes his synthetic Moon rocks into bracelets for Belldandy, Urd, and Skuld to derive power from, but he mentions that they'll only last about a month before they have to be swapped-out. Urd complains about this short duration before leaving, but Belldandy tells Keiichi that it's her sister's way of thanking him.
Alone, Urd feels like she's slipping deeper and deeper into Keiichi's debt and wants to pay him back somehow. She spots Belldandy knitting a sweater for Keiichi nearby and gets frustrated watching her, believing that her passiveness is why Keiichi hasn't made a move yet. Now, she decides that she will brew a "Super Deluxe" love potion for them.
In her room, Urd mixes various exotic ingredients in a flask and lets it distill for two hours while she rushes to another room to watch a soap opera on TV. Skuld then starts calling for her because she wants today's newspaper and is drawn to her room by the potion's aroma, and inside she finds the newspaper under the chemistry equipment, as Urd is using it to catch any dripping liquid. She grabs the paper with both hands and swiftly yanks it off, but she accidentally trips one of the beakers and spills its contents on the floor.
Not wanting a repeat of the terrible punishment she endured the last time she messed with Urd's chemistry, Skuld quickly builds a small vacuum machine called "Kyupon Inhaler-Z" and uses it to suck up as much potion as she can, but she only gets a tiny amount of it and hastily dilutes it with another chemical to make up the difference. After she leaves, Urd returns to perform a magic incantation on the modified liquid, surprised by how much smoke it creates.
Outside, Urd goes to Belldandy and offers her a piece of "candy" that she made from her potion. While a worried Skuld watches from a distance—unwilling to interfere out of fear of being punished—Belldandy accepts Urd's candy and eats one of them, though she doesn't react as Urd expected her to. Urd leaves disappointed, but unbeknownst to either her or Skuld, Belldandy's heart suddenly begins beating faster.
Keiichi is tinkering with his motorcycle when Belldandy sneaks up from behind and hugs him. While Keiichi panics at how aggressive Belldandy is acting suddenly, Belldandy asks him to take her shopping. In downtown Nekomi, Keiichi gets a box of Pocky and offers one to Belldandy, but she instead grabs the one Keiichi is holding with his mouth with her own, but the stick breaks before they kiss. Now, despite saying she wanted to shop, Belldandy now wants to watch a movie with Keiichi. In the theatre, Belldandy holds his hand and closes her eyes to entice Keiichi into kissing her, but he doesn't and instead feels like he's trapped in a dream.
What happened at the theatre keeps Keiichi distracted later on as he tries doing his homework just when Belldandy enters his room. She partially undoes her clothes and leans on his body, saying that she "really likes" him. This move makes Keiichi panic and he hops away from Belldandy— worried about crossing a line with her and suffering emotionally if and when the woman he loves eventually has to return to Heaven—but Belldandy confesses that she wants to get as close to him as she can. Frustrated, Keiichi hugs Belldandy on the floor.
Performing a nightly inventory of her ingredients, Urd discovers that some of what she hadn't used is mysteriously gone, and there is a strange-looking machine in place of her alarm clock. She immediately goes to Skuld and makes her confess to what she did earlier, and listing the extra ingredients she put into the potion, Urd realizes that Belldandy has become a "seething cauldron of desire".
While Keiichi is talking to Belldandy about how he likes the "normal" her, he is glancing away and doesn't notice Urd suddenly force another piece of candy into her mouth. When Keiichi looks at Belldandy, she has turned back to normal, and hearing Keiichi's words makes her hug him again and say that she loves him.
Urd is pleased with the outcome, but Skuld cries about Keiichi stealing her sister away. Now, Urd follows through with punishing Skuld, forcing her to build several machines that serve no practical purpose, including one that does nothing but goes in a circle.