|This article is about a/an ally in Denji Sentai Megaranger.|
Ken Ooiwa is the homeroom teacher of the five Megarangers during their civilian lives as students at Moroboshi High School. He's a rather lazy, slacking teacher who rather oversleep instead of going to school, upsetting good students such as Kouichirou. However, he is a caring teacher who does look out respectfully and with authority for his students. He is so devoted to his position that he even decides to stay at Moroboshi High for the sake of his students even as others decide to run away in the face of monster attacks, believing someone has to stay behind to take care of them. Also during the finale, he was shown as the only faculty member that not had abandoned the Megaranger, and while he had to stop Erina from getting into a verbal fight with the principal, the two of them, alongside Jirou Iwamoto, would later start the pep rally to cheer the Megarangers on that would be instrumental to their final victory against Dr. Hinelar.