Let's start with it, step by step.
Plot: 3/10
Poor, nothing new, maigc, a school, teenage, world in crisis... we've seen it at least 100 times this year only. So, if you're going to show the same thing to us again, make something new. Nobody will remember the show in 5 years.
Art: 6/10
It's not that bad, it's not memorable, but I don't have big complains about it. It's easy to watch and the magic effects are nice.
Sound: 5/10
Didn't want to get my hands on the OST or the singles after watching the show and, for me, that's a bad sign. I don't remember music calming a scene or raising tension.
Character: 8/10
Oddly, this is the strong part of TS. The Main Character is not the typical harem lead, it's cynical enough and wants to watch and grab boobs, and that's new.
The harem itself isn't that bad, too much focus and a few wasted characters, but their personalities aren't that bad and are well designed.
Enjoyment: 3/10
I started the anime. Watched the first 6 episodes. Abandoned it. Started again a year later and finally was able to finish it. You don't WANT to watch TS, you just feel the need to finish it so you can forget everything about it.
Overall: 4/10
If you like superficial plots, silly ecchi, some big boobs and some crappy spells this thing maybe is for you. If you hace an ounce of self esteem don't waste your time in it.
