This anime should be accompanied by a checklist, let's see...
Introspective, eyepatched loner hero traumatised by a tragic back story... CHECK
Dedicated younger female friend who wants to get closer to him... CHECK
Hero's best mate with an unhealthy obsession with the opposite sex... CHECK
Best mate's female buddy who clobbers him every time he lusts after other girls (Which is LOADS) CHECK
Strange new girl at school who doesn't say much yet follows the hero around for yet-to-be-revealed reasons... CHECK
Strange new boy at school who seems to hate the hero for yet-to-be-revealed reasons... CHECK
And that doesn't even begin to explain the Red Moon appearing in the middle of the day and the disgusting creatures with tentacles that emerge during these periods. Or the red haired sword-wielding girl we see during the intro (Great theme tune BTW) who I'm sure will have a major role. Remember: this is only a review of the first episode, but by the looks of things we've got quite a few OTT battle scenes ahead, as well as short skirts and breasts with a life of their own galore.
So, a pretty bog standard Japanese cartoons, with all the elements neatly stacked in a predictable, but entertaining way. I'll watch a few more. 6/10