His sister is such a bitchy pathetic loser it's kind of endearing and cute. Talking all that smack while being just as much of a nerd as her brother and not being able to handle any sort of criticism, she's great.
No wonder Rihito deals with Noa so easily since he had to grow up with a sister like that holy Moses. And I adore that Rihito loves his doggo so much, it looks like the true vacation has begun for him.