The first season alone is one of my favorite anime of all time. The characters are compelling, the romance between the two main characters is not at all cliche, and the female love interest isn't just a damsel in distress; they both rely on each other equally. The music, from the opening/closing themes to just the soundtrack, is completely what makes this anime so fantastic. It pulls you into the anime very effectively.
The second season, however, resorts to anime cliches. A brother/sister romance, a damsel in distress female love interest, rape, molestation, and tentacles. Not a bad anime as a second season, but disapoints compared to the first.
