Aoi was summoned by the Rumooku Kingdom from Land of Rich Autumn Harvest Empire Japan.
He has somewhat long hair even though he's a boy. He has biggish black eyes and is 132 cm tall. He's also has girlish face.
He was disguised as a girl while accompanying Menea Rumooku en route to the Royal Capital as her attendant. During which, their entourage was attacked by a demon. It was later defeated by Satou and his party.
Kuro was intrigued by the lighter Porina presented him. He asked for a meeting with the inventor. Porina set a meeting with Aoi. Kuro introduced himself as a Japanese named Echigoya. Although from a different Japan, he was elated that he met a fellow Japanese. He was informed that the Echigoya firm won't sell the lighter. He was dismayed when he heard this. He won't be able to make a new one because of the lack of funding when asked by Echigoya on what was the next invention. He was asked to join the Echigoya Firm as an inventor and advisor, Aoi accepted. He was also given one gold as a starting salary. He also wanted to introduce Echigoya to his Sensei.
Aoi led him to the downtown workshop.