Has anyone ever thought about what hugging Ralsei would actually feel like? The game describes him as "fluffy" very frequently, but that only paints a picture of how his fur feels. To get more information, we have to dig a bit deeper. Susie says "[Ralsei] is practically a walking teddy bear" and indeed his strength stat isn't very high. Given he's lived a life of solitary study, it's unlikely he has much muscle, which is reflected by his strength stat being the weakest among the trio, and he will be outperformed by Kris and Susie in just about every physical activity, relying on magic to keep up with them (and potentially also implying his low body weight). You could safely assume hugging Ralsei would feel like hugging nothing more than a soft, malleable ball of fuzz.
Imagine surprising him with a hug as so frequently happens in the game, the shock causing him to put up the feeblest resistance for but a moment, before steadily accepting the embrace. He's not strong enough to get away from you as your arms sink past his fur and right into his soft, uncalloused skin, with a high body temperature and beating heart clearly audible as you bring your head over his shoulder. He wouldn't even try to put up a fight, and would just be forced to accept it, confused but bashful as he always is. You could hold him for hours. If he were to reciprocate, it'd be like having a blanket wrapped around you, with only just enough force to keep you close but still in control. This is what Kris feels every time you choose to do this in game. Think about that.