There's a good story buried in here, but they didn't really find it, I feel. Like, at the end of the episode they drew a contrast between Taiyou and Kyouichirou and their responses to the fear of losing someone they love, which is a solid idea to start from, but they just sort of fumbled it. To start with, they didn't do enough legwork to set up Taiyou as having that fear be his driving motivator, so the comparison feels very lopsided. And then, when he decides to join the family, he says he'll protect Mutsumi - the exact thing that is Kyouichirou's flaw. The contrast they're going for ends up ringing hollow. On top of that, they couldn't make Kyouichirou just a doting and overprotective brother but instead he's a siscon perv. It's all very frustrating because this premise is exactly the sort of anime nonsense that I love to see (cast of weirdos? marriage of convenience between (i assume) mutual crushes? unrealistic spy shenanigans? hell ya)
Can't really give this higher than a 3/5, unfortunately