Octodad hugging Fujimoto at the end of the game, while stating that he loves all humanity. In blubs.
Not only is the fact that he'd forgive the chef for all the trouble he's caused sweet, but it may help Fujimoto recover from his murderous paranoia regarding marine animals trying to take over the world.
Octodad's family's lack of reaction to finding out he's an octopus. They're a little shocked at first, but go back to treating him like normal almost instantly.
The sheer love of Octodad for his family. Even when he's trying to distract his wife from arguing with him by submerging her with plushies, he's doing it because he doesn't want to leave his family.
Looking back at the interactions between Stacy and Octodad after you find out that Stacy knew all along he was an octopus, Stacy insisting that her "octodoll" will protect her from monsters is incredibly sweet.