You're thinking of Darker than Black. It was stylish and had great production values, it just didn't really have a heart.
GL repeatedly and clearly illustrates the central themes of progress, evolution and maturity, culminating in an epilogue that features the main character turning down the chance to recover everything he's ever lost, and leaving the universe's fate in the hands of the next generation. This seemingly anti-climactic ending shows he has come to understand that learning to accept your losses and to be humble are part of growing up. As Simon himself said, he's not cut out for the job that would have otherwise been pressed upon him, which is why we have Hobolock instead of GARlock.