He loves the FL, but he's not in love with her. He doesn't see her romantically, he's basically just a dude with major siscon, that's how it is. In his eyes she's a pure existence, so he doesn't want her to be tainted by the impurities of men, which is probably why he himself also wouldn't want to be romantically involved with her.
As the story progresses he'll obviously come to see her in a romantic light, and when that happens he will cut off other women, but his yandere tendencies will still remain, like being controlling of her actions, not wanting her to ever leave his side, and his overprotectiveness, especially against males will significantly increase.
Now it's obvious that this kind of character isn't exactly a good person, and these traits aren't things that anyone should see as romantic in real life, but I'm just clarifying that he's even though he's crazy, he wouldn't cheat on her, because he's a yandere character in a Shoujo.
As for Raise wa Tanin ga ii, Kirishima is a crazy ass masochist with mental issues and most importantly...it's Seinen, I'm not even sure Kirishima has romance in store for him in the future at all.











So after all Kainer's talk about seed and Vali Ahad, we didn't get to see any beautiful bi-racial babies?ಥ‿ಥ. I'm hoping the author gets an okay on the side stories, and maybe and epilogue too.
Well, it was cute and sweet...and kinda short now that I really look back on it, felt a little longer since I was waiting for chapters.