Oki Mariner Crew#
Selkie has a good relationship with all the crewmembers of the Oki Mariner. He can be strict with them, but in general, he's great with his crew and values their work and effort very much, both when they are on mission and when they are in port. For their part, the crew all respect him unconditionally, valuing both his abilities as a hero and as captain of the Oki Mariner, though they still find his attempts to be cute embarrassing.
Sirius#
Of all the members of his crew, Selkie has the closest relationship with his sidekick Sirius. He highly values her abilities and work efficiently together when on mission. Thanks to her Good Ear Quirk, Selkie sends him a message in morse code using the echolocation abilities of his Spotted Seal Quirk without the enemy being aware of it and even if they are at a great distance from each other. All of this could be seen when Selkie was tricked and trapped in a ship's hold. Despite this, he managed to warn Sirius of the situation and trust her to find the hideout of the villains while he was looking for a way to escape.[1]
As with the rest of the crew, Selkie can be strict with Sirius, but she also does not hesitate to reproach her captain, especially when he tries to be adorable. Sirius is the most open to showing her disagreement with this behavior, reminding him that he looks too tough and macho to be cute and the only thing he does is look ridiculous, which leaves Selkie morally dejected.
U.A. High School#
Tsuyu Asui#
Selkie gets along very well with Tsuyu since she trained alongside in the internship. He always refers to Tsuyu by her hero name, Froppy, and treats her like a full-fledged hero rather than an intern. However, due to her inexperience during the time, Selkie tried to avoid Tsuyu being involved in hero works, but congratulates her when she does the right thing in a dangerous situation.[1] Selkie was happy when meet her again several months later for a mission, and this time he no longer doubts her abilities and capabilities to be a hero, taking her with him to find some smugglers.[2]
Tsuyu is one of the few people who finds the captain adorable when he attempts to make himself look cute.