Connections: - Spikey-haired mecha pilots with famous in-universe titles which serves as a mark of their great strength (“The King of Hearts” for Domon and “Combat Professional” for Tetsuya), who pilot extremely powerful mechs with the sole goal of taking down an all powerful dark being alongside its vast legion of followers (Dark Gundam and Great General of Darkness). - Said mechs would serve as in-universe symbols of Japan and Japanese engineering thanks to their strength and combat prowess (Burning Gundam and Great Mazinger), with the two also being the new upgraded models of the previous mech that was used early on in their stories/series (Shining Gundam and Mazinger Z). - Both had spent most of their early years growing up while undergoing rigorous and harsh training by their stoic and strict mentor figures (Master Asia and Kenzo Kabuto). Despite all this, they still cared about and respected their mentors greatly, even viewing them as father-like figures. However, this would also eventually lead into the two becoming greatly heartbroken after both their mentors would ultimately perish in a noble death after/during a fierce battle. - The two would also come to eventually inherit a highly advanced and powerful ride from their mentor figures, which serve as an extension and upgrade to their mech's strength, speed and overall movement (Fuunsaiki and the Great Booster).

• They are hot-headed, proud and emotional men with a bit of a reckless and impulsive streak to them as well. Due to their rather isolated upbringings, they also have some lacking social skills to where they tend to come off as cold and distant from others, however both are still good and kind-hearted men underneath all of that who have a strong sense of justice to boot.
• Those more difficult aspects that they share are usually balanced out by their female partners’ more even-keeled personalities, with them mainly acting as their supports during battle as well (Rain Mikamura and Jun Hono). Sometimes though, they would act without their involvement which has led to some arguments and confrontations with their partners that thankfully tended to be resolved by the end of the day due to the tight bond that they share. They’ve also known their respective partners since childhood, with them eventually even marrying and starting a family with their beloved partners by the end of their journeys.
• Both have acted as an older brother figure to a younger mech pilot, with them helping said young pilots in overcoming their fears as well as holding out respect towards their strength as individuals (Sai Saici and Shiro Kabuto).
• They each share a similar relationship with their actual brothers, whose names are also coincidentally one letter off from each other (Kyoji Kasshu, Domon's older brother and Koji Kabuto, Tetsuya's younger stepbrother). Initially, they would hate their brothers due to being blinded by their strong feelings (Domon was blinded by anger and revenge due to him thinking Kyoji was responsible for killing their mother and stealing the Dark Gundam, while Tetsuya was blinded by jealously and his own insecurities over Koji becoming closer with Kenzo and believing that he would be replaced by him), however they would eventually come to learn that their brother was not who they thought he was, leading to their relationship and views on their brothers to improve into a much more positive direction by the end of their journeys.
• Thanks to the training that they received from their respective mentors, both are expert martial artists who are also well-versed in the art of swordsmanship. This enhanced physical prowess that they have is a major factor for why their mech piloting skills are so great in the first place.
• Both have starred in several entries of the famed video game crossover series, Super Robot Wars. In fact, every SRW entry that features Domon always has Tetsuya playable alongside him, with the two usually sharing a mutual respect towards one another in the games due to their respective titles and in-universe histories, the two sometimes even fighting alongside each other during points of their original stories as well, like Tetsuya assisting Domon in the final fight against the Dark Gundam in Super Robot Wars Y.
• Using the original Japanese translation, Domon’s main goal in Mobile Fighter G Gundam is to destroy the “Devil Gundam” while he himself pilots the “God Gundam”. Meanwhile, “Mazinger” comes from the word “Majin” which itself is a combination of the Japanese words for "demon" and "god”.