Robot competition is held with the theme of decommissioning of nuclear reactor organized by Ministry of Education, Culture, Sports, Science and Technology: MEXT since 2016. The competition is called ”HIRO creative RoboCon”. We participated in the competition for two years. For the first year, we challenged the random step competition. For the second year, we challenged the mock-up stairs competition. This report summarizes the outline of the competitions for the past two years.