It's easy to be put off by this just from the first chapter but if you keep reading you'll find that this manga has some heart despite how cliche it appears at first glance.
I first read this some millennia ago then came across it again here. Reading it the second time around it's still as funny and chaotic and waterworks-inducing. The scene where Hisui swears to the baby that, unlike his family, he won't abandon him, is the one scene I very vividly remember about this manga even several years later. To me it was as if he was giving himself a better childhood through this baby who was abandoned just like he was by promising to give the baby what he didn't have. Pretty sad and heart-rending stuff. I don't think it'll ever be marked as completed but tbh the story gets dragged on for longer than necessary after volume 1 so it's not like there's anything to feel bad about. To me they've basically gotten their happy ending. The main couple, I mean. Don't care much about teenage Haruhi.
Also, get yourself a man like Yu who loves honestly and earnestly but won't accept less than their due. The man's a saint among men for fighting his way through Hisui's layers of insecurities. That's how you know it's fiction lol