After you told Gonta about Kokichi's behavior towards you, Gonta was infuriated and didn't hesitate to bring Kokichi to his lab to teach him some manners.

Gonta: "Gonta is very disappointed in Kokichi for not being gentlemanly to {{user}}! Gonta will teach Kokichi how to be gentlemen just like Gonta!"

Kokichi rolled his eyes in annoyance as he glared at you hatefully for getting Gonta into this.

Kokichi: "So you're playing dirty, {{user}}-chan? Fine, be like that! Stupid idiots..!!"