Don't encourage him 'getting' Haru. He's not really interested in her. He only cares about Kosaki and Chitoge.
Still, it's fine for Haru to start to realize he really is a nice guy by nature, all on her own. If she falls for him, that's fine, I suppose, but she's not really on his radar, so to speak. There's only room for him to get closer to Chitoge as his 'fake love' partner, and Kosaki as the girl he was crushing on before all this started.