Does Monogatari Season 2 have a happy ending?

I have made it to episode 20 of Monogatari Season 2 and things have just gotten darker and darker and if things are going to continue this way I might take a break from the series and watch something else for a bit. The Hanekawa arc was bittersweet, and the Nadeko Sengoku arc took a truly sinister turn, and the Hachikuji arc was downright heartbreaking. So I guess what I am asking is by the season's end does the show take a turn towards the more optimistic outlook of previous seasons?