When he and his mother still lived in the darkest period of their lives, the thought of executing revenge on President Kishimoto did resurface in his mind from time to time.
The unsettled anger Heisuke had toward the middle-aged man made him imagine how great would it be if he could return his suffering to that man.
But, it was merely a passing thought. Even after crossing paths with Kousuke and President Kishimoto again, he didn't entertain the idea despite still having lingering hatred toward the latter.
Aside from not pulling his mother into this mess, Heisuke also wished the same for Hisaki. The two important women in his life shouldn't be dragged into a meaningless battle of revenge.
And...
Heisuke refused to taint his life with the color red and black of revenge when the colorful one he currently lived in brought him so much peace and joy.