Misato-san wa Amasugi Joushi ni Chotto Kibishii - Vol. 5 Ch. 33

[wallsg]

I thought it was explained? He used to be married, and he thought the best way to support his wife was to work extra hard and bring home the bacon. He ended up working so much that he was never home, and she divorced him. He decided to change his work ethic to "Hakuna Matata" and that he would never date again.

She was only his fiancée and not his wife. This is one of the notations I have for Konishikawa:

o) Traumatized by his breakup when his fiancée said his entire life was based on hurting and stepping over people and that "you no longer have the right to love anyone", leading him to go way too far to avoid hurting people