Water Hose

Water Horse (ウォーターホース) were Pro Heroes and Kouta's parents.

History
At some point before the start of the series, both members of Water Horse were defending a village from a villain and sacrificed themselves to save the civilians. The Water Horse duo fight the villain to the bitter end which results in their deaths, but managed to injure the villain enough to drive him away, including deeply scarring the villain's left eye; thus they saved the civilians.