Height 167 cm At first glance, Ichirou is a timid man who rarely likes to speak out, which is evident in the way that his family treats him. He retreats into cowardice and melancholy when behaviors such as hatred, selfishness, rudeness or bullying come into his way. His introversion, however, is in conflict with his need to help and support all those around him.

Spoiler

When he receives his powers he becomes a bit braver than originally perceived at the beginning of the story.

Ichirou is a middle-aged man who has been diagnosed with stomach cancer the day after moving to his new house. After finding out that he's not going to live for a long time, he runs away to a park to cry.

Spoiler

Unfortunately for him, a UFO hit the Earth on that park, killing him and a boy in the process. The aliens did not intend to kill any intelligent life and decided to rebuild his body. The Aliens only had weapons and offensive materials, and in a hurry they moved Ichirou's consciousness into a new body, which is a weapon-unit robot.

Spoiler

At the end of the series when an asteroid is about the hit the earth and destroy it, Inuyashiki self-destructs himself after Hiro and changes the trajectory of the asteroid, ultimately saving the mankind.