Shin Mazinger Shogeki! H Hen is a one-shot manga by Go Nagai to celebrate the release of Shin Mazinger Shogeki! Z Hen. It tells an original story while featuring modernized designs of the main characters. The manga was released in Champion Red on October 2009, which also featured Shin Mazinger ZERO. The manga would later be published in a composite volume called Shin Mazinger Shogeki! Super H Hen, which along with the main story contained a few extra pages for the start of the manga and the crossover manga Cutey Honey vs. Abashiri Ikka.
The story begins in Tokyo where Count Brocken released a Mechanical Beast called Zetsurion H69. Sayaka Yumi appears piloting a new robot, Aphrodite A Neo. Compared to its predecessor it possessed heightened agility for better maneuverability. Unfortunately even with this, Sayaka was no match for the Mechanical Beast and ended up being saved by Koji Kabuto and Mazinger Z. Mazinger attempted to help Aphrodite up while gloating but Sayaka just walked away angry. At the school showers, Sayaka laments that most battles against the Mechanical Beasts she always needed to be saved by Koji and Mazinger. She is asked by a classmate how her relationship with Koji is going. Sayaka replies that because of the ongoing fights they never have time for a sentimental relationship. He never even said 'I love you' or 'I like you', just try to see her naked in the bathroom.
As this happens Baron Ashura comes in with his/her Ashura Corps. He/she releases sleeping gas from its rod that puts Sayaka and the other girls to sleep. Baron Ashura then boasts about his/her new plan that involves the girls as Sayaka regains consciousness in the grip of a metal tentacle of the Mechanical Beast Gargle RD7. Meanwhile Koji noticed that Sayaka was missing and went with Boss tracking her cell phone signal. Koji finds it but Sayaka is nowhere to be found causing Koji to worry.
The Gargle RD7 surfaces and Mazinger is dispatched to defeat it. Koji then sees that girls from his school had been taken hostage naked. Mazinger manages to fight Gargle and free some of the girls from its snare. Baron Ashura only laughs as he/she reveals Sayaka. Koji is concerned for Sayaka while taking a bit of delight in seeing Sayaka naked. Ashura commands the Mechanical Beast to reveal Sayaka's private area in front of Koji a couple of times which distracts Koji long enough for the monster to continuously attack Mazinger. Sayaka continues to worry for Koji as the Mazinger is hit by missiles. But the smoke allows the Mazinger cover to use its Koshiryoku Beam to free most of the girls. Then there is a sudden blast that came from a weapon wielded by Prof. Yumi who was brought to the area by Boss's gang also bringing along Aphrodite.
With Ashura distracted, Sayaka manages to escape and board Aphrodite. Before Ashura has time to react Mazinger strikes the Mechanical Beast receiving more help from Aphrodite, rescuing the rest of the girls and destroying the Mechanical Beast. As Koji thanks Sayaka, he notices her still naked body which causes Sayaka to cover herself. Koji has the Mazinger go over to the Aphrodite to cover the cockpit so that no one but he would see Sayaka, but Sayaka rejects the offer still embarassed, with the Mazinger's hands over the Aphrodite's chest area as Koji stares at Sayaka.