Pop☆Step gives her live performance to her fans. One of them, Teruo Unagisawa tries getting closer to Pop☆Step, but another fan shoves him all the way back, knocking him down. Ichimoku Samazu and Jube Namimaru help him and advise him that it is not okay to become obsessed with Pop☆Step. However, desperate to touch his Idol, Teruo injects Trigger into his neck, causing him to transform into a eel-like Impromptu Villain.
Teruo starts to chase a terrified Pop☆Step through the streets, asking her for a handshake. Koichi sees as he leaves work, and immediately puts on his costume and heads out while encountering Juubei and Ichimaru who have been chasing after Teruo. Soon, Knuckleduster also appears, and both Vigilantes come out to face an uncontrolled Teruo.
First, Koichi tries to grab Teruo while Knuckleduster attacks him from above. However, Teruo's skin is covered with slippery mucus, making any of their attacks ineffective. Knuckleduster's punch have no effect as his attack slides off while Koichi's hold slips off as well, causing them to bump into each other. Thinking about how to deal with mucus, Knuckleduster spots an udon shop, or more directly, at the flour sacks.
Meanwhile, Teruo continues chasing Pop☆Step, but loses sight of her between the alleys. Knuckleduster and Koichi talk Pop☆Step, and manage to convince her to letting the over-enthusiastic fan shake her hand, expecting that he will back off afterwards. With great displeasure, she agrees to shake his hand, however, Teruo is not satisfied and demands a hug and then a kiss as well, coiling Pop☆Step in his slime body.
While he is distracted, Koichi and Knuckleduster throw large quantities of flour to him, which they got from the udon shop. The flour drains all the liquid from his slime, nullifying his slimy defense. Without his protective mucus, Knuckleduster gives Teruo a beating until he returns to normal.
After stopping and tether Teruo, the Naruhata Vigilantes decide to leave the place when they hear the sound of police sirens. The three return to Koichi's house to rest, while Teruo is arrested by the police.