"You once taught me Mirai. Ultraman fights for humans because they love them. That's why you can't die. It make no sense to die because of kindness."
- ―Aya's words to motivate Mirai as he fights against Yapool
Aya Jinguji (ジングウジ・アヤ Jingūji Aya) is an oceanographer who first appeared in the Ultraman Mebius & the Ultra Brothers film, and later appeared in episodes 43 and 44 of Ultraman Mebius. She acquired a GUYS member license at the age of 14.
Ultraman Mebius & the Ultra Brothers
Aya was taking a favor from Captain Sakomizu to help Mirai Hibino (Ultraman Mebius) investigate abnormal activities off the shore of Kobe. As Alien Temperor began attacking the city, Mirai transformed into Mebius and successfully defeated the alien invader. At that moment Alien Zarab infiltrated Aya's lab and captured her. Alien Zarab disguised himself Aya, and gave a glass of coffee to Mirai, which he accepted. Mirai didn't know that the coffee was poisonous. After he drank it, his body became paralyzed and Alien Zarab revealed his true form. With Mirai still paralyzed, Alien Zarab attacked the city in the form of Mebius. Later, by using immense efforts, Mirai finally transformed and defeated Alien Zarab. Soon after Alien Guts and Alien Nackle ambushed Mebius, so the Ultra Brothers came to help him. After Alien Guts was finished off, U-Killersaurus was finally resurrected. But Yapool betrayed Alien Nackle and destroyed him. The Ultra Brothers fought with U-Killersaurus, but to no avail. When Mebius was about to destroy U-Killersaurus' head, he saw Aya trapped in a crystal in the forehead of U-Killersaurus. When Mebius was about to be killed by U-Killersaurus, the Ultra Brothers combined with Mebius, resulting in Mebius Infinity. Mebius overpowered the ultimate Choju and saved Aya. After the battle Mirai thanked her for her help and flew back to the Phoenix Nest.
In episode 43, she visited Phoenix Nest to see her grandfather and invited Mirai to spend a day with her. When Mirai and Aya walked into a park, they were followed by a Hyena-reporter, Hirukawa. Suddenly, a mysterious man wearing black clothing with balloons approached Mirai. He told him that he was Yapool. He released a gold strip-red balloon to sky. The sky cracked and a portal opened for Mebius Killer to jumped to earth. Mirai told Aya to take cover. But he didn't know that he was being followed by Aya and she saw Mirai transform into Mebius. When Mebius was about to lose against Mebius Killer and was exhausted, Aya cheered him up that "It make no sense if you die because of kindness, please stand up." Mebius stood up again and fought once again and destroyed Mebius Killer with Mebium Dynamite. After the battle was finished, the floor below Mirai, Aya, and Hirukawa stood in was cracked and sent them to Yapool's dimension. They saw the city was destroyed. Hirukawa attacked and hurt an exhausted Mirai for GUYS didn't exist while the Earth was attacked. Suddenly, the black costume man, Yapool, appeared again. He ordered Hirukawa if he want to save Aya, he must shoot Mirai with the gun that Yapool gave him. Hirukawa, with no other choice, shoots Mirai and Aya. But Mebius uses the Mebium Defensircle to protect him and Aya. Yapool attacked Hirukawa for the failure.
Yapool tried to persuade Mirai why he must protect bad men like Hirukawa and asked Mirai to join Yapool, but Mirai refused. When Yapool had the answer, he transformed into his true form and Mirai transformed to fight him, but Yapool overpowered Mebius. Aya once again tried to cheer him up him, but it was useless and Mebius's eye was about to close. But, Ultraman Ace told to him via telepathy that Mirai's friends would always be connected to his heart. Once again, Mirai stood up again and changed into Mebius Burning Brave. This time, Mebius overpowered him and destroyed Yapool. In the end, Mirai, Aya, and Hirukawa came back to Earth. When Mirai and Aya rest in park while waiting for Phoenix Nest to return from the moon, Aya thanked Mirai and kissed his cheek, which made Mirai felt shy and confused.