The episode is followed up by What Kind of Person Is Dad?.
Sakutarō uses his vacuum cleaner robot named Mambo to clean the household, while Airi sits and watches him control his robot. Although convenient, she told him it's bothering her since she says she can use magic since they have the Jewelpets with them. However, Ruby and Labra are lazing about. Sakutarō continues berating magic over science, but Airi continues arguing with him. She tries to get Ruby and Labra to demonstrate their magic, but they fall asleep, much to her disappointment. So Sakutarō says he has made his point, but the girls continue to go against his ideals. So Sakutarō decided to prove to the girls once and for all science is better than magic, by inventing a "Mecha Jewelpet" that can do everything a Jewelpet can. The girls become astonished, while Luna intrigues herself to see what he can do.
Sakutarō begins working on his mecha Jewelpet project in his room. During work, Ruby, Labra, and Larimar come in to show off their talent of using their magic to do various of their respective chores. Such as doing the laundry, making pizza, and a specially brewed tea with magical milk. This leaves Sakutarō with various suggestions, all while being challenged science could not do any of the other Jewelpet's magical work. By midnight, Sakutarō falls asleep due to tiredness. Luna on the other hand, was watching his dedicated work from the distance.
The following day, Sakutarō completes his invention and shows off his latest work: The Mechanical Jewelpet. He activates it and makes him do every in the house, from laundry to carpentry and even phone business. Everyone were surprised, though Luna to herself, respects him.
The Jewelpets were still not impressed. Ruby, Labra, and Larimar later challenged the Mechapet to various things requested by themselves. They later start making lots and lots of more requests on the Mechapet. Being flooded with too much information, the Mechanical Jewelpet malfunctions and goes on a rampage throughout the town. Everyone chases after the Mechapet and Sakutarō tries to stop it. Eventually, the Mechapet jumps into a river and becomes submerged underneath.
Sakutarō becomes dismayed losing all his hardwork and effort. Luna feels sympathetic for him. Then, Airi's pendant glows and transforms into magic power. It then fuses with Luna, magically changing her into her human form. With her magic, she casts a spell to grab the submerged Mecha out of the water. Then she reverts back to her regular form.
The Mechapet later breaks down due to the malfunction. Luna feels sorry for not being able to help the Mechapet. In Sakutarō's demise, the other girls cheer him up by saying it was impressive either way. Sakutarō appreciates their encouragement. He grabs onto Luna, thanking her for showing her magic to him that made him realize an importance...But selfishly proclaims he should of made Mechapet waterproof, much to everyone's surprise. In spite of his ego, Luna is only glad Sakutarō is back to normal.
- Luna's spell that she used to rescue Mechapet is modeled after Moses, a historical figure who was mentioned in Crossing the Red Sea narrative from the Book of Exodus.