Knight Leader of Melromarc/Relationships

Naofumi Iwatani
Like most Melromarc noble people, the Captain disliked and looked down on both the Shield Hero and demi-humans, while blatantly favouring the other three Heroes. However, he couldn't avoid witnessing (and even, begrudgingly, recognizing) Naofumi's party's bravery in several situations, especially when they protected Princess Melty.

Ren Amaki, Itsuki Kawasumi, and Motoyasu Kitamura
As with most of Melromarc’s nobles, the Captain blatantly favoured these Heroes in spite of Naofumi being the actual Hero who did most of the heavy work in fighting the Waves and other dangerous situations.

Malty S Melromarc
Though not much is clearly shown, it can be assumed that the Captain was in good terms with Malty, always endorsing (though not verbally) her arbitrary actions with great satisfaction.

Ake
For hierarchy matters, the Captain was Ake's superior and constantly commanded him to assist the other Heroes in detriment of Naofumi and any demi-humans, and also greatly disliked Ake's sympathy towards the Shield Hero's party. During the pursuit of the Shield Hero, he attempted to slaughter Ake and his friends for supporting the Shield Hero.

Vice-Captain
He was the Captain's direct right-hand man, though the latter apparently didn't notice (or possibly belittled) the Vice's decision to assist the Shield Hero in the Riyute Village against the Wave monsters.