Your request is a bit wrong, nice and cheery + good story isn't really a great mix and I haven't ran across many good anime like that. The reason for that is that good stories can't be all happy time 100%, they need some drama or something like that. On the other hand, the "nice and cheery" anime tend to be slice of life with little or no story. With that said, I would suggest Chuunibyou demo Koi ga Shitai! - MyAnimeList.net!. While it doesn't exactly fit the description, that's the closest you're gonna get.