Class 3E's unexpected adventure

One-day, Yuma and Maehara were talking about Isogia's siblings, which shocked the some of his classmates since many didn't know he had any siblings. This intrigued Koro-sensei's interest, which in turn had him decide that the class should have a special day where they could bring their younger siblings. However, a strange turn of events seems to have taken place. A formidable force seems to be lurking in the shadows with only the promise of a downward spiral of events. What sort of events you may ask?

Well....

Stay tuned to find out