I don't think that Hosaka has ever done anything to make himself seem of questionable moral character. Yes, he's definitely odd, but he seems like a good guy.
Three minute croquettes? Assuming this is the standard Japanese "korokke" with potatoes and beef, I hope that doesn't include cooking time due to the potential for food poisoning. I don't think Hosaka is the sort of chef who would write a recipe with microwave cooking times in mind.
It's nice that Hosaka got Haruka to taste one of his cooking concoctions even if she prepared it herself.