Where is Nobuhiko?

1 BLACK!! Transform 2 The Monster Party 3 Mysterious Cyborg Mystery 4 The Devil's Laboratory 5 Kotaro in a Maze! 6 The Secret Sight Enigma 7 The Living Machine Restored 8 The Devil's Trill Sonata 9 The Crimson Lips of Bishum 10 Where is Nobuhiko? 11 The Hungry Monsters 12 A Super-Bike Legend Is Born! 13 Mama Raises Monster Babies! 14 The Day All Tuna Vanished 15 Assault on a Haunted School 16 Friend From Across the Sea! 17 Kyoko's Mysterious Dream! 18 Sword Saint Birugenia!! 19 The Suffocating Trap of Hell 20 Rider's Grave 21 Clash! Super Machines 22 The Shadow That Stalks Dad 23 Marmo's Magical Powers 24 The Female College Student's Nightmare 25 The Roaring Armed Machine 26 Rescue the ESPer Girl 27 The Fire Breathing Danger Road 28 The Scarab Beetle's Invitation to Hell 29 The Targeted Death Mask 30 Aloha to the Assassin! 31 Burn! Boy Warriors 32 Dream Girl Yuki 33 Father, Son, and the River of Love 34 Revival? The Prince of Hell 35 Fight! The Two Princes 36 The War Declaration of Love and Death 37 Memories in the Yubari Sky 38 Mystery? EP-Party Boy Squad 39 The Idol's Evil Power 40 The Karate Master's Secret 41 The Dangerous Time Thief 42 Tokyo Mutant Gathering 43 The Mutant Farm Battle 44 An Ocean Inside the Closet 45 Death of Flower Mutant Bishium 46 Fierce Death of Baraom 47 Rider Dies! 48 A Bouquet of Reminiscence to the Sea 49 Fierce Battle! Death of Darom 50 What is the Creation King's True Form? 51 Gorgom's Last Day