He is a decent human being for the most part
We only seen him malicious once when he was angry because he didn't fully comprehend what a rental girlfriend is; then that he tried to blackmail her once and stalked her a couple of times. Other than that we have the constant lies though most of them are to protect his grandma's smile or to help Chizuru keep her secret. The lying wasn't about how much of a pathetic human being he is for some time now.
He is really awkward and has a very pervy imagination, but what can he do, when there is so much cute girls around him, for no apparent reason.
Actually my biggest gripe with him is that he claims he is in love with Chorizo, but that doesn't stop him from still renting her as if nothing changed.