Invisible bodyguard

Shizuka's parents have to go out and won't be home that night, leaving her alone. Nobita is worried, so he, Gian, and Suneo ask her if she wants them to go keep her company, but Shizuka politely declines. Worried about Shizuka, Nobita asks Doraemon to bring out the "Invisible Shadow" to protect her. In the evening, the two call to Shizuka's house to check on her. However, they still can't sleep that night, and, using the excuse that "It's wrong to worry about my future wife's safety," they even persuade Doraemon to go with them. In reality, their worries are unnecessary; Shizuka isn't worried or scared at all, happily watching TV since no one is watching her. Nobita and Doraemon begin testing the reliability and safety of the "Secret Protection" system. They even use the "Disaster Preparedness Device" to create fake earthquakes and fires, which frightens Shizuka. After the lights are turned off, Shizuka is even more terrified by the "Invisible Shadow". A power outage in town makes Nobita realize Shizuka might see the bodyguard, so he runs to her house. A frightened Shizuka also runs out of her house, and the two meet on the street. Nobita, seeing Shizuka's distress, tries to help her but is bullied by the bodyguard. Finally, Shizuka comforts Nobita, who tries to ask Doraemon for help, but Doraemon is still asleep, leaving Nobita crying and begging for help.