Fear of Summer Vacation!

""Netto and Meiru go out to collect insects during their free time of summer vacation. While chasing an insect, they unknowingly entered a mysterious area and they could not go back! The two reach a certain tower and encounter Mistman of the cyber world's tower. At that time, Swordman and Coldman come and try to draw Mistman to Nebula, but he refuses them. With the cooperation from Yuriko, a dimensional area is formed and Swordman and Coldman encounter Netto. Although Netto Cross Fuses and battles, the 2 against 1 fight becomes bitter. But then Mistman appears there and..."" - Courtesy of Heat Man