In the 2011 manga ULTRAMAN, there are several side characters who, while not being main characters are important parts of the story. They are not members of the SSSP or opponents to the protaganist, but their own individual stories tie in with Shinjiro's even if only indirectly, meaning they are still important to the story.
- Yosuke Endo
- The detective in charge of investigating a series of murders. The veteran detective and his partner Kurata were bafled as how the strange murders could have been committed, before they could continue any further they were called of the case by the SSSP's agents lead by Moroboshi. Later, upon coming upon a traffic accident Endo tried help a trapped truck driver, but his partner held him back on the premise it was to dangerous. Both were surprised when Shinjiro landed infront of them in his Ultraman Suit and rescued the bus driver from a fire by slicing of his side of the compartment. The two immediately began to question the young boy and Endo spotted the SSSP crest on the suit. When the young boy took of he declared that it was not an Ultraman they had just seen.
- Endo returns to the crime scene and eventually learns about aliens resolving to investgate any crime involving strange possibilities and the SSSP.
- Endo's younger partner and subordinate, he was assisting the older detective in the serial killings and was there was when he was called of by the SSSP. Later he was driving Endo, presumably home, when they happened upon a traffic accident. Endo was about to go and help but Kurata held him back, the truck could explode at any minute. When Shinjiro arrived in his Ultraman suit the pair, Kurata thought it was some form of cosplay, but was surprised at the young man's speed, strength and jumping ability. When Shinjiro saved the bus driver the two were quick to question him but the young man suddenly left. Kurata wondered aloud if that was an Ultraman only to have Endo denounce the boy as such.
- Kurata later followed Endo back to the seen of a crime they had been called of, they found no clues except that the victim was a Rena fan. Outside they found themselves chasing after a little boy, only to discover what the SSSP was hiding, there were aliens on Earth.
- Rena Sayama
- A young Idol around Shinjiro's age, Rena became a fan of Shinjiro's after his numerous crime fighting exploits wearing his Ultramans suit. While her agent just denounced him a cosplayer, Rena was quick to defend him as the real thing. While on their way to an appointment, the two were stuck in a strange traffic jam caused by Shinjiro's battle with another alien. The pair landed nearby with Shinjiro landing on the hood of their car. While the alien belittled Shinjiro and destroyed his confidence, Rena and her agent had snuck out fo the car. Hearing her hero being trash-talked, Rena called out Ultraman and gave him back his confidence. Unfortunately this angered the petty alien who fired Plasma bombs at her. Fortunately Shinjiro was able to stop the attacks with his Spacium Blades.
- After the battle she went to the hospital to be treated for minor injuries when she ran into her dad Endo, who was releaved she was alright. Unknown to either of them the Four eyed alien watched them drooling from outside.
- An information broker living with in the Alien City, Jack was the only human resident of the city somehow living a comfortable life, in fact Moroboshi stated he refused to leave. When he was first met by Shinjiro he had just won a boxing match with an alien combatant, winning by Knockout showing his skills as a boxer but implying he may not be a normal human being. He later get's Shinjiro into a fight with Red, the former champion of the ring before Jack beat him. Afterwards he assists the SSSP and Shinjiro in various ways with the case.
- Mino, Saeki, and Ando
- Alien Igaru's human companions and fellow fans of Rena.
- Alien Igaru
- A member of an unknown race on Earth, the creature was the size of a dwarf or young child. It was an avid if not disturbed fan of the idol Rena, getting upset to the point of childish raving and drooling when someone spoke ill of Rena on one of the internet chatrooms it visited. When Kurata and Endo were checking out the home of a recent victim of a string of strange murders he ran when the detectives called out to him. The alien proved to be faster than a normal human, and more durable as well as it was hit by a car and knocked out for a little while. When Endo saw it face it awoke and took before either policemen could do anything. As of now this alien seems to be the prime suspect of the murders Endo was investigating which do not fit the method of feeding used by Alien Adacic.
- After Shinjiro's battle, the same alien spied on Endo and Rena from outside the hospital.
- The former champion of the Alien City arena, the former king of the arena lost his eye and title in a match with Jack. He later appears when Jack was talking with Shinjiro, ready for payback, but Jack somehow tricked him into fighting Shinjiro instead
- Alien Kadder
- A small time crook, the alien broke into a warehouse and killed the guard, his action drew the attention of the SSSP who mobilized an extermination team to capture or destroy him. While he tried to snipe them from above, his tactic failed and he was forced to flee from their return fire, only to run into Shinjiro who took him down. The alien begged for his life and Hayata was merciful leaving him to be taken into custody. It was later stated he had killed seven people. The creature showed no superhuman abilities save perhaps durability as he fell through a floor with Shinjiro on top of him, he was also armed with a weapon that fired bolts/spikes.
- Alien Bris
- An assassin sent to kill Endo and Kurata after they had set a trap for the alien serial killer both they and the SSSP were investigating. When the policemen's firearms proved useless against it exoskeleton they were saved by the arrival of Moroboshi who battled the alien.
- Residents of the Portal City
- The myriad of aliens from different species all living in a single city. Despite their different origins they live in a city partaking in activities not very different from Human cities. They have markets, gambling rings and even a criminal underworld which is a source of trouble for the SSSP and ultimately humanity.
- The legendary Giant of Light, years ago he accidentally killed Shin Hayata as he chased a monster to Earth, feeling sorry he revived the human by merging with him. Later after his battle with Zetton he was forced to separate from Hayata, leaving him with what is now called the Ultraman Factor, which he passed on to his son.