S1·E42 Just like Dogs, Rats, and Bulldogs

Nagi, perplexed by Hayate's apparent lack of weaknesses despite being a main character, plots ways to find chinks in his armor. As her various schemes fail to produce results, Maria, Sakuya, and Isumi get swept up in the flow and discuss their weaknesses as well. Hayate and Wataru begin studying German in preparation for a Hakuō mathematics exam, while Maria tells Hayate a bit of background information on Isumi, Sakuya, and Wataru. When they go to check on Nagi and Wataru, Nagi becomes jealous that they are alone together, prompting Maria to remark that Hayate's weakness seems to be not understanding the female heart.